In this article, aMIMOantenna system featuring wide bandwidth, high gain, and circular polarization for 5G communication networks is presented. The proposed antenna enabled high data rates, enhanced signal reliability, and improved performance in dynamic and challenging 5G environments. Wide bandwidth ensures compatibility with various 5G frequency bands, while circular polarization allows for better signal propagation and reception, particularly in non-line-of-sight scenarios. In that regard, the present paper addresses an enhanced bandwidth 4-port circularly polarizedMIMO antenna to encounter polarization mismatch along with high data rates. The suggestedMIMO antenna comprises four identical patches strategically positioned in orthogonal orientations in such a way as to provide the circular polarization direction. Meanwhile, the bandwidth is extended by inserting straightforward defected ground structure (DGS) and L slots. TheMIMOantenna offers an impedance bandwidth covering from 24 GHz to 28.8 GHz and an axial ratio bandwidth of 62% within the overall band. It demonstrates excellent performance with a high peak gain of approximately 14.84 dBi. Additionally, it exhibits strong isolation of more than 20 dB among the closely packed antennas, ensuring reliable communication and minimizing interference. The combination of these features in a MIMOantenna system is crucial for meeting the demanding requirements of 5G communication, including increased data capacity, low latency, and reliable connectivity. The simulated and measured outcomes exhibit robust concurrence, signifying a high level of accuracy. Consequently, the suggested MIMOantenna appears well-suited for the 5G bands designated for deployment in the USA (27.50-28.35 GHz) and Europe (24.25-27.5 GHz).

This paper introduces an innovative band stop filter specifically designed to reject a sub-6GHz band within the 5 G spectrum. Fabricated on an FR4 substrate with a relative permittivity of 4.4, the filter incorporates a defected ground structure (DGS) and features very compact dimensions of 19 mm × 11 mm × 0.8 mm. The filter design is performed using the High Frequency Structure Simulator (HFSS). Besides, the filter’s equivalent circuit is modeled using the ANSYS circuit editor. A parametric study has been conducted to identify the optimal parameters for the filter’s form and size. The proposed filter exhibits a rejected band of 1.42 GHz, spanning from 2.3 GHz to 3.72 GHz, with a center frequency of 3.18 GHz. Within the rejected band, the S21 value is less than −21.36, and the stop band fractional bandwidth (FBW) is 44.65%. Additionally, the filter demonstrates a negative group delay (NGD) characteristic in the frequency range of 2.97 GHz to 3.35 GHz, with a measured NGD time of −0.42 ns, and a quality factor equal to 2.24. These results underscore the filter’s suitability for applications utilizing frequencies below 2 GHz and above 3 GHz, ensuring efficient functionality.

In this paper, a complementary split ring resonator (CSRR) loaded compact CPW-fed circular shaped monopole UWB antenna with dual band notch characteristics is designed on an FR-4 substrate. The propounded band-notched UWB antenna is integrated with two frequency selective surface layers referred as bandpass frequency selective surface (FSS-1) and reflector (FSS-2) to offer enhanced radiation performance. Bandpass FSS-1 enhances the gain of the antenna by improving directivity and reflector FSS-2 reflects back the backside radiation of the proposed antenna towards the forward direction thereby increasing gain and directivity of the proposed antenna. Furthermore, a two-element orthogonal MIMO antenna is proposed with improved gain using two FSS layers. The complete configuration of the proposed two-element MIMO antenna consists of CSRR-based radiating patches, monopole ground planes and two integrated FSS layers. The proposed MIMO antenna operates in UWB range from 3.46GHz to 16.02GHz with dual notches at 3.9GHz and 7.2GHz. Isolation between MIMO elements is greater than 23 dB. Both antennas are fabricated and investigated at 5.9GHz for vehicular communications. Maximum gain improvements of 8 dB and 6.4 dB are observed in case of the presented single element and MIMO antenna within the entire operating band due to the integration of dual FSS layers. The diversity performance of the suggested MIMO antenna is investigated by analyzing mean effective gain, envelope correlation coefficient, channel capacity loss and diversity gain parameters. The proposed MIMO antenna is a suitable candidate for vehicular and UWB wireless communication applications.

This article introduces the development of a Multi-Input Multi-Output (MIMO) antenna array specifically designed for 5G millimeter-wave (mm-wave) communication systems. The suggested MIMO configuration consists of four antenna arrays, each comprising two elements arranged evenly, operating at 26 GHz and 37 GHz with a physical size of 43 mm × 32.5 mm × 0.8 mm using a Rogers RT/Duroid 5880 substrate. The proposed MIMO configuration provides dual bands, with frequency bands extending from 23.8 to 30 GHz (IBW = 6.2 GHz) and 32.5 to 41 GHz (IBW = 8.5 GHz), accompanied by high gains of around 18.5 dB for the first band and 16.4 dB for the second band. The designed antenna also shows broad circular polarization with 3 dB Axial Ratio Bandwidth (ARBW) of 4.75 GHz, ranging from 25.05 to 29.8 GHz. A physical prototype has been fabricated for the proposed 4 port MIMO antenna array and tested to verify the results acquired from simulations. The comparison between simulation and measurement results in terms impedance and radiation parameters such as S-parameters, isolation, gain, axial ratio (AR), efficiency, radiation patterns, and various necessary MIMO metrics demonstrates a strong alignment. This antenna covers various 5G New Radio (NR) application bands such as 28 GHz n257 (26.50-29.50 GHz), 26 GHz n258 (24.25-27.50 GHz), 28 GHz n260 (37-40 GHz) and 28 GHz n261 (27.50-28.35 GHz) utilized across different countries including Canada, Australia, China, France, Germany, India, Italy, Japan, South Korea, United Kingdom, and United States of America.

This paper introduces an arrangement of a Multiple-Input Multiple-Output antenna array implemented specifically for operating within the THz frequency bands. The antenna is designed for short-distance THz communication links. A quad-port MIMO antenna configuration has been chosen to function across three frequency bands. Each cell element is situated on top of a silicon substrate. The combined cross-sectional surface of the MIMO antenna is 70 × 50 µm². The proposed MIMO antenna device reaches the following three frequency bands: 2.6–7.9 THz, 9.66–10.3 THz and 11.5–14.1 THz. In addition, the mutual coupling coefficient is less than − 20 dB, indicating strong isolation between antenna elements. This high isolation is obtained by using a defected sibstrat structure and a specifique distance between antenna elements. The MIMO array antenna attains peak gains of 11.88 dBi, 8.78 dBi and 10.65 dBi when operating over the three cited bandwidth. Furthermore, the suggested MIMO structure exhibits favorable characteristics with CCL < 0.5 bps/Hz/sec, MEG ≤ –3.0 dB, ECC < 0.01, and DG ≈ 10 dB, over the operating bands. Based on the results obtained and compared to several works reported in the literature, the proposed implementation maintains a good size-performance compromise which allows better adaptation to applications requiring versatile performance in various communication scenarios.

Fifth-generation (5G) technology is extremely important in the current context since it seeks to fix the shortcomings of its predecessors, the 4G generation. To achieve this goal, this project entails constructing a small ultra-wideband (UWB) MIMO antenna featuring an anti-parallel layout, designed for operation within the millimeter-wave spectrum. Moreover, the investigation scrutinizes and fine-tunes the mutual coupling interaction between the two elements in detail. The presented MIMO antenna occupies a small footprint of 6 × 17.37 mm2. Despite its compact dimensions, this MIMO antenna provides an impressive isolation of 65 dB, attributed to the adequate inter-element spacing and the anti-parallel arrangement. Additionally, the integration of a defected ground structure (DGS) enhances isolation by approximately 20 dB. Furthermore, the proposed MIMO antenna demonstrates a satisfactory gain of approximately 6 dBi, boasting high efficiency surpassing 96 %, and lying between 34.1 and 39.7 GHz. The proposed antenna has undergone simulation and analysis utilizing both the High-Frequency Structure Simulator (HFSS) and Computer Simulation Technology (CST) in order to confirm its utility. Based on these findings, the suggested MIMO antenna appears to be well-suited for compatibility with 5G communication systems, specifically covering the n260 band (37–40 GHz) and the Ka-band.

In this paper, the performance of Optical Wireless Communication (OWC) under atmospheric turbulence and pointing errors is enhanced by employing MIMO transceivers and heterodyne BPSK and DPSK modulations. We have derived new closed-form expressions for the bit error rate (BER) of MIMO optical wireless communications based on BPSK and DPSK with heterodyne detection for atmospheric turbulence only, pointing error only, and both effects combined. Numerical simulations reveal that the effect of turbulence and pointing errors increases with Rayleigh variance and normalized jitter variance, while it diminishes with normalized pulse width. The BER values for SISO-BPSK and SISO-DPSK, considering a normalized pulse width of 4, normalized jitter of 2, Rayleigh variance of 2, and SNR of 16 dB, are 7.50×10-3 and 1.48×10-2, respectively. It is evident that the BER of SISO OWC experiences significant degradation for both modulation techniques. However, through the employment of a MIMO transceiver with an increased number of receivers and transmitters, the BER experiences a substantial reduction. The BER values for MIMO-BPSK and MIMO-DPSK under the same conditions are remarkably low, standing at 1.24×10-12 and 2.38×10-10, respectively. These results underscore that, for both SISO and MIMO systems, BPSK outperforms DPSK. The power penalty of SISO-BPSK, for Rayleigh variance and normalized pulse width, is twice that of MIMO-BPSK under the same conditions. The results show that we can use MIMO with heterodyne BPSK to reduce the BER caused by atmospheric turbulence and pointing errors.

In response to the escalating demand for high data rates and the expanding user base, multiple input multiple output (MIMO) technology has recently become of paramount importance in addressing the imperative for high-capacity communication systems aligned with emerging standards. In this paper, a single antenna element that achieves a wideband frequency coverage by adjusting the slots ‘dimensions and a satisfactory gain of 6.4 dBi is presented. To enhance the antenna's gain and capabilities, we introduced a MIMO antenna designed to operate within the frequency range of 36.8 to 40.9 GHz. The proposed MIMO antenna configuration consists of two-element arrays etched on a compact 25.94×26.76×1.3 mm³ Rogers RT/duroid 5880 substrate. While maintaining the operational band and enhancing gain, a critical challenge involving inadequate isolation between the two antenna elements is encountered due to the confined area. To effectively tackle this issue, a parametric study on the inter element distance between antennas is conducted and Defected Ground Structure (DGS) is implemented. This refinement results in a substantial 3.6 dB enhancement in isolation, which is found to be lower than -31 dB, a notable improvement in impedance matching, and a remarkable high gain of approximately 7.7 dBi is achieved. Besides, the analysis of the MIMO metrics demonstrates that they consistently fall within acceptable ranges, with the antenna showcasing an envelope correlation coefficient of approximately 0.005 and a commendable diversity gain of around 9.99 dB. The proposed antenna's combined attributes, including its compact, simple, and low-profile design, position it as a highly promising choice for 5 G communication system and future miniature devices intended for Internet of Things (IoT) applications.

This article presents a meticulously engineered MIMO antenna system tailored specifically for 26 GHz millimeter-wave applications. It integrates a compact planar-patterned metamaterial (MTM) structure, carefully designed with split square and hexagonal unit cells to realize an effective near-zero index (NZI) range for both permeability and permittivity. Comprehensive wave propagation analysis along the y-axis rigorously examines the MTM's characteristics. The antenna system showcases impressive technical attributes, including an extensive 8.7 GHz bandwidth, notably highlighting mu-near-zero (MNZ) characteristics spanning over 8.7 GHz wide frequency spectrum, and epsilon near zero (ENZ) properties covering 8 GHz (26–34 GHz). Notably, a 4-ports MIMO antenna design is adopted with each element meticulously crafted using a 4-unit cell array configuration. The designed 4 × 4 MIMO antenna is fabricated using Rogers RT/duroid 5880 substrate and it occupies a compact dimension of 45.5 × 45.5 × 0.8 mm3. Experimental validation reveals compelling performance metrics, including a bandwidth spanning from 24.3 to 30.9 GHz, isolation levels below − 25 dB, and a maximum peak gain of 15.48 dBi. Additionally, the antenna exhibits circular polarization characteristics, maintaining an axial ratio below 3 dB within the frequency bands of 25.35 to 28.05 GHz and 28.10 to 29.83 GHz. Furthermore, the fabricated MIMO antenna demonstrates outstanding diversity parameters, exemplified by a high diversity gain (DG > 9.99), low envelope correlation coefficient (ECC < 0.0001), minimal channel capacity loss (CCL < 0.5), and total active reflection coefficient (TARC < − 8 dB). The suggested MTM-based MIMO antenna system with sophisticated design and exceptional performance could be an exemplary choice for seamless integration into the evolving landscape of 5G NR networks, particularly those operating within the n257/n258/n261 bands.

Low-density parity check (LDPC) codes, are a family of error-correcting codes, their performances close to the Shannon limit make them very attractive solutions for digital communication systems. There are several algorithms for decoding LDPC codes that show great diversity in terms of performance related to error correction. Also, very recently, many research papers involved the genetic algorithm (GA) in coding theory, in particular, in the decoding linear block codes case, which has heavily contributed to reducing the bit error rate (BER). In this paper, an efficient method based on the GA is proposed and it is used to improve the power of correction in terms of BER and the frame error rate (FER) of LDPC codes. Subsequently, the proposed algorithm can independently decide the most suitable moment to stop the decoding process, moreover, it does not require channel information (CSI) making it adaptable for all types of channels with different noise or intensity. The simulations show that the proposed algorithm is more efficient in terms of BER compared to other LDPC code decoders.

The ever-increasing demand for wireless communication services, driven by the proliferation of mobile devices, the surge in data-hungry applications, and the expansion of the Internet of Things (IoT), has placed immense pressure on available bandwidth resources. In response to this pressing issue, researchers and engineers have turned to MIMO technology as a promising solution. In the context of future fifth-generation (5G) terminals, achieving optimal isolation while maintaining a compact size remains a formidable challenge. This challenge arises from the increasing demands placed on 5G devices, which require efficient and high-performance antenna systems in constrained form factors. Until now, numerous antennas utilizing metamaterials have been proposed. However, a comprehensive review based on key enhancement techniques is still lacking in the literature. Consequently, we aim to conduct a comprehensive examination of the numerous types of 5G metamaterial-based single and MIMO antenna designs in this study.

OFDM (Orthogonal Frequency Division Multiplexing) is a widely used modulation technique in many standards such as Wi-Fi (Wireless Fidelity), LTE (Long Term Evolution), and 4 G. It allows for high transmission data rates and excellent spectral efficiency. However, one of the main limitations of OFDM is its high PAPR (Peak-to-Average Power Ratio). In this paper, we will first describe some methods to reduce the PAPR associated with OFDM signal. We will discuss some methods such as the clipping, the Selective mapping SLM, the Partial Transmit Sequence (PTS), and the Tone Reservation (TR). Let's list their advantages and disadvantages before focusing on the TR method which we will detail. This work aims to improve the performance of the TR method in terms of speed of convergence and reduction of the PAPR, using the conjugate different algorithms while respecting the frequency specifications of the IEEE 802.11a standard. The proposed algorithm which is based on the gradient method, Conjugate gradient methods, and Quasi-Newton method shows good performance regarding PAPR reduction and speed of convergence. The choice of an appropriate technique depends on several factors: required PAPR reduction, acceptable complexity, and performances (spectral efficiency, latency, etc.). A trade-off must be found in practice between these different criteria. It has been shown that the Quasi-Newton method algorithm with its two variants converges more quickly.

The 5G system generally requires the transmission of significant amount of information in allocated frequency bands. Besides, 5G channel presents two major problems for wireless communications, namely time dispersion, due to the phenomenon of multipath propagation, as well as frequency selectivity. So, improving the reliability of a wireless communication system for 5G requires the use of more suitable modulation techniques and more performance in the wireless context. Among the modulations that can be considered for this kind of application, we find the CPM (continuous phase modulation) scheme. This class of modulations is robust to phase drifts and nonlinear distortions generated by the amplifier when it is pushed to its maximum output power. In this paper, we propose a non-coherent receiver insensitive to fluctuations in the modulation index and capable of offering better performance on 5G channels. A detailed description of CPFSK signal is performed. The blind equalizer was introduced in order to combat inter symbol interference of the 5G channel as well as to make the transceiver insensible to the variation of the modulation index. The obtained results show the robustness, efficiency and low complexity of the proposed system over 5G channel.

A novel antenna system that utilizes multiple-input and multiple-output (MIMO) technology to suit the requirements of 5G applications is proposed in this article. The antenna has a wide operating bandwidth and high isolation in n257/n258/n261 5G bands. The suggested arc-shaped MIMO antenna is composed of four similar patch units with modified ground planes arranged in a four-port configuration and is made on a Rogers RT/duroid 5880 substrate, which measures 31.891 × 37.5885 × 0.508 mm3. The prototype of the suggested MIMO antenna is realized to confirm the obtained simulated results and validate the proposed design. The four-port MIMO antenna features a broad frequency range of 7.3 GHz from 21.8 to 29.1 GHz, a peak gain of 5.76 dBi at 29 GHz, and a good isolation less than −18 dB. The proposed antenna's MIMO performance is evaluated by analyzing several diversity parameters. The findings of the evaluation demonstrate an envelope correlation coefficient (ECC) value of less than 0.001, a diversity gain (DG) value exceeding 9.995 dB, and an average mean effective gain (MEG) of −3 dB within the operational frequency band. The suggested MIMO antenna's compact size and impressive performance make it a suitable choice for intended n257/n258/n261 5G NR networks.

A high-isolation wideband MIMO (Multiple-Input Multiple-Output) antenna, shaped like a palm tree, is designed for 5G wireless communication purposes. The propounded MIMO antenna is formulated on an FR4 substrate, featuring a quartet of ports and adhering to a precise dimension of 45 × 50 × 0.8 mm3. A detailed analysis of the proposed high isolation wideband palm tree shaped MIMO antenna, considering its bandwidth, gain, isolation, radiation patterns, and diversity performance metrics such as diversity gain, channel capacity loss, mean effective gain, and total active reflection coefficient, is presented. The results obtained from simulations and measurements demonstrate good agreement, indicating the antenna's effectiveness for intended applications. Indeed, an extensive bandwidth covering a range of 11.6 GHz from 23.4 GHz to 35 GHz is achieved by demonstrating superb reflection coefficient. Additionally, the design reports remarkable isolation and a peak gain of 12.4 dB, indicating its ability to enhance signal strength. One of the most notable features of this MIMO antenna is its coverage of multiple 5G bands, making it ideal for use in various geographical regions, including the USA and Canada (27.5–28.35 GHz, 37.0–37.6 GHz, and 37.6–40.0 GHz), China (24.75–27.5 GHz), Korea (28–39 GHz), Japan (27–29.5 GHz) and Sweden (26 GHz).

Artificial intelligence (AI) is now affecting all aspects of our social lives. Without always knowing it, we interact daily with intelligent systems. They serve us invisibly. At least that’s the goal we assign to them: to make our lives better, task by task. Artificial intelligence has the potential to make biology education more engaging, personalized, and effective by providing students with interactive simulations, personalized learning experiences, and other tools that help them understand complex biological concepts. In this paper, we discuss the integration of AI into the virtual classroom, which significantly enhances student learning experiences in various ways. The study shows that an effective integration of technology into the virtual classroom requires a thoughtful approach that aligns with educational goals and the specific needs of students. In fact, interactive simulations can help make biology more engaging and memorable for students. Besides, personalized learning AI algorithms can help biology students receive a more tailored and effective learning experience, helping them to better understand the course material and develop a deeper appreciation for the natural world. In this work, we will discuss the use of AI to enhance interactive simulation-based cellular processes, with additional application in anatomy, physiology, and ecology teaching. Moreover, this paper discusses how AI could be used to analyze student data and propose personalized learning using adaptive assessments, content recommendations, and data sciences. This paper illustrates examples of AI algorithms that could be useful for teaching biology.

In a wireless communication chain, filters play a critical role in ensuring the efficiency, reliability, and overall performance of the system. In fact, filters are essential for selecting specific frequency bands. They can narrow or widen the bandwidth, depending on the requirements of the communication protocol. Appropriate bandwidth management is crucial for optimizing data transmission rates and accommodating multiple channels within the available spectrum. This article describes the design of a compact bandpass filter with two identical rectangular open-loop resonators. The proposed filter frequency response covers the 3.5 GHz global interoperability for microwave access (WiMAX) and fifth generation (5G) applications. The structure of this filter uses the Rogers RO6010 substrate, which has a dielectric constant of 10.2, thickness of 1.27 mm, and tangent loss of 0.0023. The proposed device is intended for wireless communication systems operating at 3.5 GHz. The filter offers a wide bandwidth of 1.21 GHz with a small size of (5.72 × 12.34) mm2, and a low insertion loss of −0.16 dB. The suggested filter offers effective utilization across various applications including fifth-generation (5G), sub-6G, and WiMAX. Simulation and optimization of the proposed design are conducted utilizing the HFSS (High Frequency Structure Simulator) software. To corroborate the results from HFSS, the ADS (Advanced Design System) software is employed. The simulation outcomes obtained from both HFSS and ADS simulators demonstrate close resemblance.

This paper describes a four-port MIMO antenna array design featuring bow-tie-shaped slot-loaded patches with wideband capabilities that cover the frequency range from 24.2GHz to 30.8GHz. The proposed antenna design is printed on an FR4 substrate and occupies an area of 25×24mm2. The MIMO antenna consists of four antenna arrays that are symmetrically placed in an upper-lower configuration. The bow-tie-shaped slots loaded radiators are separated horizontally by 3.48mm and vertically by 5.94mm. Each antenna array contains two elements that are separated by a distance of wavelength/4. The suggested MIMO antenna array delivers a high gain of 19.09 dB at 27.8GHz and has a bandwidth of 6.6GHz that covers the frequency band of 24.2-30.8GHz. The research demonstrates the quality of the proposed MIMO antenna through various diversity parameters such as mutual coupling, port correlation, diversity gain, and data rate that can be transmitted over a communication medium. The simulation results are validated and found to be consistent with the experimental results. The presented antenna covers the entire bandwidth allocated to different regions, including Europe (24.25-27.5GHz), Sweden (26.5-27.5GHz), USA (27.5-28.35 GHz), China (24.25-27.5GHz), Japan (27.5-28.28GHz), and Korea (26.5-29.5GHz). The proposed MIMO antenna design could be an excellent option for 26/28GHz 5G NR n257, n258, and n260 bands under mm-wave wireless communication systems.

A compact eight-port MIMO structure containing planar inverted-F antennas (PIFAs) as radiating elements is designed for 5G cellular communication applications within the sub-6 GHz band. The proposed antenna consists of four radiating elements that are placed at four corners on the same plane of geometry. The overall dimension of the ground plane is considered to be 59 mm × 120 mm to make it convenient for modern smart mobile handsets. Each radiating element has 2-feeding plates, which are situated perpendicular to each other in orientation to make the arrangement cross-polarized, which in turn exploits polarization diversity as well as spatial diversity among the combination of different radiating elements. The patches are structured by embedding rectangular slots in a meandered shape, and the ground plane is configured by introducing rectangular slots and narrow metallic strips. The prototype of the prescribed MIMO PIFA model has been fabricated and experimentally tested. It shows multi-band operations (3.27–3.37, 4.16–4.35, 4.93–5.06, and 5.47–5.68 GHz) within the sub-6 GHz spectrum. The isolation among various patches is observed within the range of −35 dB to −42 dB. The peak gain reaches around 8.1 dBi. The designed MIMO PIFA exhibits superior diversity performance by producing ECC ≤ 0.0006, DG ≈ 10 dB, CCL < 0.20 bits/Hz/s, and MEG ≤ −3 dB. Furthermore, the specific absorption rate (SAR) is evaluated according to the standard values of fat, skin, and muscle at 3.3 GHz. The prescribed model maintains acceptable SAR values for 1-g and 10-g tissues, which makes it suitable for smartphone applications.

This book provides an overview of the most common techniques and methods employed in wireless fields. Conversely, it delves into a detailed study of millimeter-wave (mm-wave) and terahertz (THz) systems, with a focus on various schemes for transmitting and receiving electromagnetic waves. The title comprehensively reviews key elements associated with wireless communications, emphasizing the generation and detection of mm and THz waves. It explores specifications, innovations in new materials for high-speed terahertz and millimeter-wave technology, and considerations related to components and system aspects. Additionally, the book explores the integration of machine learning (ML) and artificial intelligence (AI) in smart communication systems, along with potential applications for advanced wireless communications. Furthermore, it concentrates on recent advances and diverse research prospects in Next-Generation Wireless Communication Technologies. The book also seeks theoretical, methodological, well-established, and validated empirical work addressing these various topics.

This chapter introduces filters in general, focusing specifically on band-stop filters and presenting the creation of an innovative band-stop filter designed specifically to reject millimeter-wave communications in the 5G spectrum. The filter’s overall dimensions are 14.8 × 3.8 mm2. The design incorporates a Rogers TMM 10i (tm) substrate. Notably, the proposed filter is designed with a rejected bandwidth spanning 6.3 GHz (24.5–30.8 GHz), a center frequency at 27.2 GHz, and a fractional bandwidth of 23%, demonstrating a substantial rejection capability of 41 dB. To assess the filter’s effectiveness, simulations and assessments were conducted utilizing the high-frequency structure simulator (HFSS), and its equivalent circuit was modeled using the ANSYS circuit editor. The outcomes affirm the filter’s appropriateness for applications operating below 24 GHz and above 30 GHz, ensuring optimal functionality in such frequency ranges.

An overview of the latest advances in promoting terahertz (THz) antenna performance is given in this work, along with an explanation of the necessity of addressing issues related to high loss and poor manufacturing accuracy, particularly in the context of small sizes within high-frequency THz bands. This investigation emphasizes the pivotal significance of terahertz (THz) antennas in the transfer and receipt of electromagnetic waves within the context of burgeoning THz systems, by leveraging their inherent advantages such as small form factor, broad frequency bandwidth, and high data rates. Furthermore, the research delves into the exploration of various conducting materials, including copper and graphene, as well as diverse dielectric substrates like polyimide and quartz. Given its special qualities, it has drawn more and more interest in a variety of applications. The terahertz frequency band, which is normally between 0.1 and 10 THz, corresponds to where terahertz antennas are intended to function. They play a crucial role in transmitting and receiving terahertz signals for various applications. Besides, antenna arrays involve the use of multiple antennas working together as a system. In the context of terahertz, antenna arrays can enhance directivity, gain, and overall performance. Furthermore, Multiple-Input Multiple-Output (MIMO) technology involves using multiple antennas for transmitting and receiving data simultaneously. MIMO systems are employed to improve communication performance by increasing data rates and reliability. In addition, the choice of materials and substrates is critical in the design of THz antennas. Different materials can affect the performance of antennas, and researchers might explore various substrates to optimize characteristics. This paper will delve into the existing challenges and obstacles faced in the development and implementation of THz antennas. Challenges might include issues related to fabrication, efficiency, signal propagation, and integration into practical systems. This comprehensive investigation encompasses THz antennas, antenna arrays, and MIMO antennas, aiming to elucidate their unique characteristics and performance attributes across different materials and substrates. Finally, in the latter section of this paper, the persisting challenges in the realm of terahertz (THz) antennas are introduced.

Our study introduces a novel technique for modeling terahertz (THz) patch antennas called the wave concept iterative process (WCIP) method. It is widely recognized for its effectiveness in analyzing complicated electromagnetic structures, especially those that fall within the THz frequency range. We describe in detail the WCIP method for antenna design, highlighting its mathematical foundations and computational aspects. Simulations demonstrate the effectiveness of WCIP in revealing the electromagnetic behavior of THz patch antennas, providing a comprehensive view of performance parameters. The discussion rigorously analyzes the results, by comparing the return loss results over different iterations to increase accuracy. Calculated parameters include S11 for a bandwidth of 2 THz at the resonant frequency of 9.91 THz, VSWR, impedance, admittance. The antenna is designed with a small-scale dimension, measuring 47.9 × 37.7 × 5 µm3 and is constructed using Rogers RT/Duroid material. Our work advances the understanding of THz patch antennas, providing a robust method through WCIP with applications in communication or medicine. Future research directions propose optimizing the application of WCIP in THz antenna analysis by integrating machine learning approaches.

The paper introduces a new, innovative, and groundbreaking ultra-compact antenna design with extremely small dimensions of 130 × 260 × 112 nm. This antenna design is capable of resonating at an exceptionally high frequency of 170 THz, which is a remarkable achievement in the field. Additionally, this antenna boasts an impressive bandwidth of 44,000 GHz, further solidifying its significance and potential applications. This novel antenna design leverages the patch antenna configuration, which is a well-established and widely used design approach. By utilizing this configuration and combining it with the compact dimensions mentioned earlier, the researchers have successfully developed a 2 × 1 Multiple-Input Multiple-Output (MIMO) antenna system. This system is a significant advancement in the field of antenna technology, as it offers enhanced capabilities and performance. To further enhance the functionality and practicality of this antenna system, a plexiglass housing has been incorporated into its design. This housing is made of high-quality plexiglass material and measures 90 × 58 × 1.5 nm. The inclusion of this housing not only adds to the overall durability and stability of the antenna system but also provides an additional layer of protection. When it comes to the materials used in the construction of both the antenna and the plexiglass housing, high-quality glass substrates have been utilized. These substrates exhibit excellent characteristics, such as a relative permittivity of 5.5 and a mass density of 2500. These properties contribute to the overall performance and functionality of the antenna system. Furthermore, the circular patch elements of the antenna system have been meticulously spaced at a distance of λ/2. This specific spacing has been chosen to enhance the resonant properties of the antenna system. By carefully positioning these elements, the researchers have been able to optimize the performance and efficiency of the antenna system, further showcasing the level of detail and precision that has gone into its design. In terms of potential applications, this cutting-edge antenna technology holds tremendous promise in the field of telemedicine and remote surgery. Due to its compact size, high-frequency operation, and enhanced data throughput capabilities, this antenna system has the potential to revolutionize communication systems in these domains. By enabling seamless and high-resolution data exchange, this technology could significantly advance the quality of healthcare services in remote or telemedical scenarios. Overall, the introduction of this novel ultra-compact antenna design, along with its various components and features, marks a significant milestone in the field of antenna technology. The level of innovation and technical expertise demonstrated in its development suggests that this technology has the potential to make a lasting impact in various industries, particularly in the realms of telemedicine and remote surgery.

This document introduces the creation of an innovative bandpass filter with Ultra-Wideband (UWB) designed for the fifth-generation applications. This filter employs an H-shaped resonator positioned at the center of a rectangular resonator, both integrated on a substrate Rogers RT/duroid 5880 type, featuring a dielectric constant of 2.2, an attenuation tangent of 0.0009, and a thickness measuring 0.5375 mm. This substrate is placed on a ground plane of the same area, measuring 40 × 59.52 mm2. The simulation result of the proposed UWB bandpass filter exhibits a bandwidth range [25.75–29.7 GHz] with reflection coefficient is − 15 dB and an insertion loss of around − 2.8 decibels. To evaluate the UWB bandpass filter’s performance, other simulations have been conducted, such as VSWR and surface current distributions, which show satisfactory results. Due to its high performance, the proposed filter is desirable for 5G applications.

Radio frequency identification (RFID) is a technology that enables the identification and tracking of objects or individuals at a distance and by sending a signal from the reader through electromagnetic waves to the tag, in turn the antenna of the latter receives these waves and feeds the chip that interprets the information and sends it to the reader in the same way. In this paper, we analyze the analog design and layout of an ultra-high-frequency (UHF) RFID tag utilizing the advanced features of the Cadence software. This work will provide an in-depth examination of the circuit simulation process, with a primary focus on achieving comprehensive simulations of the entire circuit while optimizing key parameters. We present the analog design of a VDD voltage generator for a radio frequency identification system and more particularly the design of a passive RFID tag in the UHF band at a frequency of 900 MHz and in CMOS 180 nm technology. By delving into the intricacies of the UHF RFID tag design, we aimed to explore the potential for optimizing performance, enhancing reliability, and further advancing the capabilities of RFID technology in this specific frequency range. Through meticulous design and layout methodologies, we strive to develop a robust and efficient UHF RFID tag solution that aligns with industry standards and best practices.

Transmission over terahertz (THz) bands faces some challenges such as the LOS and NLOS components. These issues are all the more topical as the transmitted speeds increase exponentially. Therefore, we need a strong communication system in order to transmit data correctly over this channel. The family of multi-carrier modulations of which Orthogonal Frequency Division Multiplex (OFDM) is a part makes it possible to respond to this challenge by using sub-carriers that are not very sensitive to multi-paths and frequency selectivity, which are easy to equalize. Moreover, the use of linear precoding allows better use of the frequency diversity of the channel. It also offers greater granularity in the choice of flow rates, thus growing the suppleness of the system. It is essential to emphasize that the accumulation of the linear precoding function comes with a minimal increase in the complexity of the system. For these reasons, we will focus on the linear precoding technique on OFDM modulation (LP-OFDM) and the additional advantages presented by this LP-OFDM technique for our study in order to understand the interest of having recourse to this additional operation. In this paper, we propose a LP-OFDM to improve the performance of a wireless communication system in terms of throughput.

Microstrip bandpass filters are the core part of wireless communications. They help refine the signal and ensure that only the desired signal reaches the receiver. Microstrip bandpass filters are the core part of wireless communications. In this paper, a compact bandpass filter is designed using two rectangular open-loop resonators. The rectangular shape is used to achieve compact size and wide bandwidth performance. The substrate used is Rogers 6010 substrate with a thickness of 1.27 mm, a relative permittivity of 10.2, and an overall filter size of 11.55 × 6.62 mm. The resulting passband has a center frequency of 2.40 GHz, a bandwidth of 1.55 GHz, a fractional bandwidth (FBW) of 64.5%, a return loss of approximately -26.3 dB, and an insertion loss of -0.1 dB. The proposed filter was simulated and performance evaluated using HFSS (High Frequency Simulation Software). The resulting performance of the proposed filter makes it very desirable for Bluetooth and Wi-Fi applications (IEEE 802.11n).

In the contemporary era, harnessing millimeter-wave frequencies emerges as a compelling strategy to fulfill the swift data transfer requirements for 5G communications. Consequently, this study involves designing a metamaterial-based multiple-input multiple-output (MIMO) antenna with a focus on achieving high isolation and gain within the millimeter-wave spectrum. The suggested MIMO is printed on a Rogers RT5800 measuring 18 × 38 × 0.8 mm3. The single antenna element demonstrates a broad frequency coverage from 27.2 to 28.72GHz. To elevate the antenna's effectiveness, a two-port MIMO configuration is implemented by introducing a second antenna element parallel to benchmark antenna. However, the isolation between the two elements is deemed satisfactory. To address this, a 4 × 1 metamaterial unit cell is introduced, significantly enhancing isolation from 31 dB to 39 dB at 28 GHz. Furthermore, it improves the gain by 0.5 dBi at 28 GHz, elevating it from 8.5 to 9 dBi. The collective features of the suggested two ports MIMO antenna, encompassing its compactness and simplicity, position it as an excellent option for upcoming portable and shrink devices in Internet of Things uses.

This research presents an innovative compact filter specifically designed for millimeter-wave communications in the context of 5 G technology. The filter is characterized by dimensions measuring 3.6mm × 1.8 mm × 0.8 mm and utilizes FR4 as the substrate material. The analysis conducted through HFSS (High-Frequency Structure Simulator) simulation facilitated a thorough examination of the filter's efficiency. The suggested bandpass filter exhibits a significant bandwidth spanning from 36.2 GHz to 39.6 GHz, with its central frequency set at 37.6 GHz. It showcases impressive specifications, including a return loss below -32.15 dB, an insertion loss of -1.3 dB, a fractional bandwidth (FBW) of 9 %, and a quality factor of 11. Particularly, the Voltage Standing Wave Ratio (VSWR) stands at 1 at the resonance frequency, with the group delay consistently staying under 91 picoseconds throughout the designated frequency spectrum. Importantly, the operational bandwidth of the filter aligns seamlessly with the frequency regulations of various countries, encompassing Australia (39 GHz), the United States (37-37.6 GHz), and Canada (37 - 37.6 GHz).

This paper analyzes lithium-ion battery datasets from NASA's Prognostics Center, focusing on battery behavior and predictive modeling. Data preprocessing reveals distinct characteristics in voltage load and capacity distribution and insights into battery degradation and temperature profiles. The study also explores correlations between variables and utilizes a Random Forest algorithm to predict battery performance accurately, achieving low Root Mean Squared Error (RMSE) and high Coefficient of Determination (R2) values. This research provides valuable insights into battery behavior and optimization strategies for applications such as electric vehicles and renewable energy systems.

This paper introduces a novel 4-element MIMO antenna engineered for prospective 5G applications. The designed MIMO antenna comprises four identical circular patches, each strategically perforated to attain the desired outcomes. The antenna's substrate is constructed using RogersRT/duroid 5880, featuring a dielectric constant of 2.2 and a height of 1.2 mm. The size of the suggested array antenna is 25 × 25 × 1.2 mm3. Employing the high-frequency structure simulator (HFSS), the suggested antenna undergoes simulation and study. Functioning as a wideband antenna, it resonates across the frequency spectrum of 25.10 to 30.52 GHz, exhibiting a substantial bandwidth of 5.42 GHz, a reflection coefficient of approximately -25 dB at 28.5 GHz and an impressive isolation under - 25 dB. The antenna demonstrates high gains of about 7.26 dBi at 28.5 GHz, a radiation efficiency around 99 % at 28 GHz, an envelope correlation coefficient (E C C)<0.01 and a diversity gain >9.95 dB, well-suited for the demands of next generation 5G use case. Specifically, the suggested array antenna spans the n 257 band (26.50 - 29.50 GHz) and the n 261 band (27.50 - 28.35GHz), which are widely utilized. Comprehensive results, encompassing return loss, gain, and various parameters, coupled with the antenna's compact size, affirm the potential utility of the proposed MIMO antenna for 5 G use cases.

We unveil a new compact dual-band passband filter crafted for the demands of 5 G usage. This filter relies on three identical spiral resonators interconnected regularly to confer compactness to the filter (6.1 × 2.3 mm2). The proposed bandpass filter utilizes for substrate 'Rogers RT/duroid 5880', characterized by a dielectric constant of 2.2, a low loss tangent of 0.0009, and a thickness of 0.5 mm. The proposed filter offers two passbands with resonance frequencies of 5.07 GHz and 7.24 GHz respectively, suited for wireless communications. The return loss is -28.68 dB in the initial passband and -40.77 dB in the subsequent one, while the insertion losses are only 0.19 dB and 0.56 dB correspondingly. Due to its compact size, low insertion losses, and ability to effectively filter two distinct frequency ranges, the proposed bandpass filter offers excellent performance, making it desirable for wireless communication systems, particularly for 5 G applications.

This study proposes a novel approach to designing reconfigurable multiple input multiple output (MIMO) antennas operating at 26 GHz. The design process begins with determining the dimensions of polygonal patches using a transmission line model, followed by the implementation of quarter-wavelength transformers for the microstrip feed lines. The antennas are constructed on FR4 substrate, chosen for its accessibility and cost-effectiveness, with specific electromagnetic properties. A 2 × 1 MIMO antenna configuration is suggested by combining traditional polygon-type patch radiation antennas on a 50 mm × 30 mm ground plane. To address impedance mismatch issues when connecting reconfigurable antennas to a common feed line, an equivalent circuit model is employed. This model incorporates lumped elements such as capacitances, resistors, and inductors to simulate the antenna's behavior accurately. Adjustments to these components are made to achieve desired S11 and S22 characteristics. The proposed design is evaluated through simulations using HFSS and AWR, demonstrating its effectiveness in achieving the desired performance metrics. Overall, this research presents a comprehensive approach to designing reconfigurable MIMO antennas, offering insights into practical implementation and performance optimization in wireless communication systems.

This research presents an innovative dual-band microstrip patch antenna featuring a rectangular slot, meticulously crafted through the utilization of the Wave Concept Iterative Procedure (WCIP) specifically tailored for terahertz frequency applications. The antenna is distinguished by its resonance frequencies observed at 19.1 THz and 28.35 THz, each exhibiting considerable bandwidths of 2.15 THz and 2.10 THz, respectively. The application of WCIP has enabled the precise characterization of current distribution patterns and electric field intensities, resulting in the optimization of key parameters such as impedance, admittance, Voltage Standing Wave Ratio (VSWR), and return loss profiles. Consequently, the finalized antenna design not only meets the rigorous demands imposed by terahertz communication systems but also capitalizes on the inherent compact nature of the microstrip patch configuration to deliver expanded bandwidth capabilities and robust dual-band functionality. These inherent characteristics collectively establish the proposed antenna as a strategically advantageous solution for the progression of high-frequency communication technologies.

Over the last decade, researchers from all over the world have become very much interested in the terahertz gap, which has a frequency range of 0.1 to 10 THz. The terahertz band can be regarded as the next frontier for wireless communications. This work is related to the design of an octagonal-shaped metasurface-based multiband super absorber for various applications in the terahertz regime. The proposed metasurface unit cell has been configured with a simple design that contains only three different layers and achieves 18 absorption peaks with more than 90% absorption levels. The desired geometry has been structured by using an octagon-shaped graphene-based radiating patch, a quartz substrate material as a dielectric space layer, and, finally, a golden patch at the bottom layer to prevent electromagnetic wave transmission. The thickness of the golden layer is taken as 0.2 µm, the thickness of the quartz substrate material is selected as 55 µm, and the thickness of graphene is considered as 1 nm. The overall size of the proposed unit cell becomes 70 × 70 × 55.201 µm3. The better performance of the proposed metasurface absorber can be obtained by fixing the chemical potential of graphene material at 0.3 eV. The proposed absorber also exhibits a polarization-insensitive nature. Additionally, the structure is also validated through an equivalent circuit approach with the support of the ADS tool and both E- and H-field distributions are explained at each absorption peak frequency. The proposed structure’s metamaterial properties demonstrate the absorber’s metamaterial nature. Based on the findings, the proposed metamaterial perfect absorber could be a suitable choice for terahertz sensing, imaging, and high-speed communication applications.

Metamaterial technology indeed holds great promise for enhancing wireless communication, especially in the development of advanced filters and devices. The use of metamaterials for filter design is an exciting and promising area of research, driven by their exceptional properties and potential for revolutionizing various technological applications. In fact, Metamaterials can be engineered to exhibit unique electromagnetic properties, allowing for precise control of the filtering characteristics. This enables designers to create filters with sharp passbands and stopbands, as well as customizable cutoff frequencies. Besides, Metamaterials can be used to miniaturize filters, making them suitable for compact and portable devices. This is especially valuable for applications with size constraints, such as mobile phones and wearable technology. Moreover, Metamaterials provide the flexibility to design filters with adjustable bandwidth. In this paper, a triplebandpass printed filter using split-ring resonators is designed and simulated. The proposed filter is composed of two split-ring arrays loaded on the transmission line. It is printed on a Rogers RT/duroid 6010/6010LM (tm) substrate. The proposed BPF has a small size (14 × 16 mm2) and high selectivity. The simulation result exhibit three passbands centered at 3.15 GHz, 6.27 GHz and 9.31 GHz, respectively with required return loss and insertion loss characteristics. The simulation studies are carried out with HFSS software and its electrical equivalent circuit model (ECM) is designed using ADS tool. The results obtained using HFSS is in well agreement with ECM results.

The primary focus of this paper is to evaluate the channel capacity of a Terahertz (THz) communication system using a Multiple Input Multiple Output (MIMO) technique. By deriving mathematical expressions for channel capacity and considering practical constraints, the paper provides insights into the performance of such systems under various conditions. The channel model used in this work accommodates the channel accuracies and transceivers constraints. To validate the proposed channel capacity, some simulations by taking into account deferent parameters namely SNR (Signal to Noise Ratio), MIMO channel Matrix size, and distance between transmitter and receiver are performed. These simulations are carried out for 3 cases which are: (1) Channel State Information CSI is known to both transmitter (Tx) and receiver (Rx), (2) CSI is known to Rx but unknown to Tx, (3) CSI is unknown to both Tx and Rx. In this study, we introduce a mathematical formulation for a communication channel tailored for Terahertz (THz) applications. Using this channel model, we analyze the capacity of the THz channel. The suggested research has the potential to be applied in the design and enhancement of Terahertz (THz) wireless communication systems, aiding in the advancement of robust and high-capacity wireless networks that can fulfill the requirements of contemporary multimedia applications.

This article describes the design of a compact band-pass filter with two identical rectangular open loop resonators for a frequency of 3.5 GHz. The proposed filter frequency response covers the 3.5 GHz global interoperability for microwave access (WiMAX). This filter’s structure uses the Rogers RO6010 substrate, which has a dielectric constant of 10.2, a thickness of 1.27 mm, and a tangent loss of 0.0023. The proposed device is intended for wireless communication systems operating at the 3.5 GHz resonance frequency. This bandwidth has a very high activity in the 1.21 GHz band, a small size of (5.72 * 12.34) mm2 and a low insertion loss of − 0.16 dB.

At present, the fifth-generation (5G) technology is of paramount importance since it aspires to account for the limitations of the preceding 4G generation. Among the multiple existing technologies, the mm-wave grabbed the researcher’s attention in an attempt to attain maximum data transfer rates and prevent network congestion. In pursuit of this objective, this piece of work involves devising a compact ultra-wideband (UWB) MIMO antenna with an anti-parallel layout specifically designed for the millimeter-wave spectrum. Additionally, the study examines and refines the mutual coupling interaction amid the two elements in depth. The presented MIMO antenna occupies a small footprint of 6 × 17.37 mm2. Despite its compact size, this MIMO antenna reached 65 dB owing to the sufficient inter-element distance and the anti-parallel arrangement. Furthermore, an isolation enhancement of roughly 20 dB is attained when utilizing a defected ground structure (DGS). Besides, the suggested MIMO antenna exhibits a satisfactory gain of around 6 dBi, offers a high efficiency exceeding 96% and covers the band 34.1–39.7 GHz. Based on the above results, the suggested MIMO antenna seems to be compatible with the 5G communication systems.

The growing popularity of IoT (Internet of Things) and its applications is evident from the increasing number of connected devices and IoT services. To enable connectivity for these devices, various wireless low-power and wide-area networks (LPWAN) have been established. In this paper, recombination mechanisms within the Receiver for IoT Based Applications were analyzed. Indeed, the principle on which the repetitions mechanism is based is simple: to emit a repetition is to increase the total energy dedicated to the information, and to increase this energy is theoretically to facilitate the demodulation of the information at the receiver stage. In this particular research, the focus is on evaluating the effectiveness of various diversity combiners employed at the receiver. To conduct the analysis, a transmission chain based on GMSK (Gaussian Minimum Shift Keying) modulation is proposed. Simulation results show that increasing the number of repetitions decreases the BER (Bit Error Rate) of the considered mechanism. Furthermore, simulation shows that the EGC (equal-gain combining) and SC (selection combining) mechanisms are very sensitive to the speed of evolution of the channel. However, the performance of MRC (maximal ratio combining) mechanism changes slightly when the transmitter speed increases; especially, at low SNR (signal-to-noise ratio).

A compact MIMO antenna with circular polarization, high gain, wide operating bandwidth, and a compact size is designed and suggested for mm-wave 5G applications. The propounded MIMO configuration contains four patch elements of similar geometries in 4×4 arrangement with individual E-shaped partial ground planes. The desired range of wide operating band with circular polarization, high gain, and high isolation has been achieved by modifying the structure of each single antenna element by integrating circular and semi-circular shaped slots in presence of rectangular slots loaded partial ground planes. The suggested MIMO antenna has been fabricated on a 1.67 mm thick Rogers RT/duroid 5870 substrate of 31.5×38.5 mm2. The fabricated and tested prototype of the suggested antenna verifies the simulation results. The suggested MIMO configuration offers a wide bandwidth of 8.1 GHz (34.4–42.5 GHz), high peak gain of about 18.5 dB and isolation of ≤−16 dB for the full working range. Besides, the presented antenna is circular polarized. This property allows the proposed antenna to emit the electromagnetic waves with a rotating electric field which allows the signal to propagate in different directions, providing better coverage and reducing the impact of signal polarization. The proposed antenna exhibits a standard MIMO performance by offering attractive diversity parameters. The proposed MIMO antenna is appropriate for 5G NR frequency band n260 (37–40 GHz) covering the allocated bandwidth requirements of different countries including UK (37–40), USA (37–37.6), Canada (37.6–40.0), and Australia (39 GHz).

This paper presents the design of a novel bandpass filter specifically tailored for 5G mm-Wave communications. The filter utilizes a rectangle loop resonator loaded with a stepped impedance line stub at its center. The overall dimensions of the filter are 11.22×13mm2. The design incorporates Rogers RT/duroid 5880 substrate with a relative dielectric constant of 2.2, a loss tangent of 0.0009, and a thickness of 0.64 mm. The resulting filter exhibits a center frequency at 22.65 GHz, with a bandwidth of 10.5 GHz and a fractional bandwidth (FBW) of 46.36%. The reflection coefficient is approximately -39.12 dB, while the insertion loss of about -0.59 dB. We conducted a parametric study to choose the optimal value concerning the form and size of the introduced slot. To evaluate the filter's performance, simulations and assessments were carried out using the High-Frequency Structure Simulator (HFSS). The obtained results demonstrate the filter's suitability for 5G applications in various countries, including the United States (24.75-25.25 GHz), United Kingdom (26 GHz), Australia (24.25-27.5 GHz), Canada (26.5-27.5 GHz), Europe (24.5-27.5 GHz), China (24.75-27.5 GHz), Japan (26.6-27 GHz), and India (24.25-27.5 GHz).

Advances in recent communication systems require minimal weight, low cost, high performance and low-profile antenna to meet the demand for next generation wireless communication devices. Due to the saturation velocity, high electrical conductivity and high mobility, graphene patch antennas are preferably used in the Terahertz band region (THz). On the other hand, MIMO antenna is usually required to compensate for the high path losses and atmospheric attenuation in THz frequency band spectrum and to offer higher data rates. In this work, a fractal MIMO antenna structure is placed on SiO2 substrate embedded with Photonic Band Gap crystal (PBG). The designed MIMO antenna structure obtains an impedance bandwidth of 1590 GHz covering an effective frequency spectrum from 1.41 to 3.0 THz with a fractional bandwidth of 72.10%. Furthermore, the proposed antenna offers peak radiation efficiency of 74.5% and gain of 4.60 dBi at the resonant frequency of 1.89 THz. The proposed MIMO antenna achieves isolation levels of greater than 25 dB throughout the entire working band and also maintains a compact dimensions of only 38 μm × 25 μm. The suggested photonic crystal-based MIMO antenna offers superior MIMO metrics like ECC ≈ (0.00000000156), DG (≈10 dB), MEG (≈ - 3 dB), TARC (≈ - 42 dB) and CCL (≈0.00000000465 b/Hz/sec) at the resonant frequency of 1.89 THz. Hence, the prescribed MIMO radiator can be utilized for various applications such as threat detection, material characterization, near field communication, detection of explosive and medical imaging in the terahertz band.

In this work, a novel multiple input multiple output (MIMO) array antenna system with a large bandwidth and high gain has been simulated, analyzed, fabricated, and measured. The proposed antenna is structured in 2×4 patch configuration along with a cross shaped ground plane loaded with four square and one circular shaped defect. The projected antenna occupies a total size of 43.611 × 43.611 × 0.42 mm3. Several slots in an elliptic form have been added to the patches to achieve the required results in terms of wide bandwidth and high gain. The MIMO antenna array is fabricated and experimentally tested to confirm the simulation results. The suggested MIMO array antenna offers an impedance bandwidth of 22 GHz covering 22–44 GHz wide range of frequencies with a high peak gain of 17 dBi at 38 GHz. The designed MIMO antenna offers superior diversity performance and it supports several 5G NR bands n257/n258/n259/n260/n261 in the mm-wave spectrum. The suggested MIMO antenna supports 5G application bands that are deployed in UK, USA, China, Europe, Canada, India, and Europe.

Purpose: This paper aims to present the design, fabrication and analysis of a wideband, enhanced gain 1 × 2 patch antenna array with a simple profile structure to meet the desired antenna traits, such as wide bandwidth, high gain and directional patterns expected for the upcoming fifth-generation (5G) wireless applications in the millimeter wave band. To enhance these parameters (bandwidth and gain), a new antenna geometry by using a T-junction power divider is presented. Design/methodology/approach: The theory behind this paper is connected with advancements in the 5G communications related to antennas. The methodology used in this work is to design a high gain array antenna and to identify the best possible power divider to deliver the power in an optimized way. The design methodology adopts several steps like the selection of proper substrate material as per the design specification, size of the antenna as per the frequency of operation and application-specific environment condition. The simulation has been performed on the designed antenna in the electromagnetic simulation tool (high-frequency structure simulator [HFSS]), and optimization has been done with parametric analysis, and then the final array antenna model is proposed. The proposed array contains 2-patch elements excited by one port adapted to 50 Ω through a T-junction power divider. The 1 × 2 array configuration with the suggested geometry helps to improve the overall gain of the antenna, and the implementation of the T-junction power divider provides enhanced bandwidth. The proposed array designed using a 1.6 mm thick flame retardant substrate occupies a compact area of 14 × 12.14 mm2. Findings: The prototype of the array antenna is fabricated and measured to validate the design concept. A good agreement has been reached between the measured and simulated antenna parameters. The measured results confirm its wideband and high gain characteristics, covering 24.77–28.80 GHz for S11= –10 dB with a peak gain of about 15.16 dB at 27.65 GHz. Originality/value: The proposed antenna covers the bandwidth requirements of the 26 GHz n258 band (24.25–27.50 GHz) to be deployed in the UK and Europe. The suggested antenna structure also covers the federal communications commission (FCC)-regulated 28 GHz n261 band (27.5–28.35 GHz) to be deployed in America and Canada. The low profile, compact size, simple structure, wide bandwidth, high gain and desired directional radiation patterns confirm the applicability of the suggested array antenna for the upcoming 5 G wireless systems.

This article presents an unique configuration of Multiple-Input Multiple-Output (MIMO) antenna array for functioning at 27/38 GHz millimeter-wave 5G new radio (NR) frequency bands applications. The suggested antenna is constructed with four MIMO elements, containing total of eight identical patches arranged in a 2 × 4 array configuration. The array also includes a separate non-connected rectangular ground plane with an overall dimension of 32.4 × 32.8 × 0.8 mm3. The single radiating patch elements are designed using spline resonator with H-shaped structures. The prototype model is realized using low cost FR-4 substrate and the obtained measurement results validate the analyzed simulated results. The suggested MIMO array antenna offers dual band operation with an impedance bandwidth of 8400 MHz covering 22 to 30.4 GHz and 8500 MHz ranging from 36.1 to 44.6 GHz. The proposed antenna achieves a peak gain of 8.75 dBi when operating at 27 GHz and 18.59 dBi at 38.1 GHz. Furthermore, it shows circular polarization characteristics by offering the axial ratio values significantly lower than 3 dB at 27 GHz and 38.1 GHz frequency bands. Additionally, the results indicate the favourable values of the diversity performance parameters with reference to Mean effective gain (MEG), Envelope correlation coefficient (ECC), Diversity gain (DG), Total active reflection coefficient (TARC), and Channel capacity loss (CCL). Moreover, it demonstrates high isolation (<−20 dB) within the desired bandwidth. These superior characteristics make it compatible for 5G NR frequency bands N257(26.5-29.5 GHz), N258 (24.5-27.5 GHz), N259 (39.5-43.5 GHz) and N260 (37-40 GHz), enabling its use in various countries including the China, European Union, Sweden, Korea, Japan, United States of America, Canada and Australia.

Thanks to THz (terahertz) technologies, it is already possible to realize very high data rate in the order of multi-Gb/s for indoor wireless links. To benefit from the properties of THz system and exploit well this technology, transmission technique must be used. For that reason, we propose in this work a CE-OFDM (Constant Envelop Orthogonal Frequency Division Multiplexing) technique to be used for THz communication system in order to reduce the PAPR problem associate with OFDM modulation. In this paper, a CE-OFDM receiver with phase demodulation is suggested. To more improve the performance of the proposed system, a frequency and phase demodulation receiver for CE-OFDM system are presented. This technique allows a nonlinear class of Power amplifier, resulting in a better efficiency of power consumption, which is highly needed for THz applications because of their limited power resources. The channel transfer function of the proposed model in terahertz band is simulated. It shows that the proposed channel presents notches especially at some frequency as the case of f = 600 GHz, 710 GHz and 935GHz. A BER (Bit Error Rate) of less than 10–4 is obtained for MMSE equalizer with 2pih = 0.5 when the SNR is superior to 15dB. Moreover, the obtained results regarding BER revealed that the performance of the proposed technique is very sensitive to the variation of modulation index. It has been demonstrated by simulation that CE-OFDM modulation outperform OFDM over THz frequencies due to the presence of linear devices such as ADC and HPA. Consequently, CE-OFDM look better tailored to support THz applications.

In this article, a compact dual-band metamaterial absorber (MMA) is suggested for the purpose of solid materials sensing in the C- and Ku-wireless bands. The proposed MMA is formed by a basic cell based on a novel shape of the folded arms square split ring resonator (FAS-SRR).The size of the cell forming the absorber is optimized for an electrical dimension of 0.27 λ0× 0.27 λ0× 0.034 λ0, where λ0 is the free space wavelength calculated at 6.78 GHz. The physical behavior of the MMA has been explored by equivalent circuit model representing the frequency response as well as electromagnetic field analysis of the FAS-SRR. The MMA is used as a solid material sensor in both C- and Ku-bands. The material under test (MUT) is placed on the FAS-SRR patch to ahave a compact structure. The direct contact between the MMA and the MUT causes shifts in resonance frequencies in the two bands which makes the sensor more sensitive. For the MUT, we tested four materials with different permittivity ranging from 2.17 to 3.55. Simulation results show that the MMA has polarization-insensitive absorption with incident angle stability up to 45° for both transverse electric (TE) and transverse magnetic (TM) modes. The proposed MMA absorbs in the C- and Ku-band with two absorption peaks near-unity; one of them is located for an absorption coefficient of 91.73% at 6.78 GHz. The second absorption rate of 99.97% is located in the Ku-band at 13.92 GHz. The proposed MMA shows good detection qualities with a sensitivity of 4.62% (800 MHz frequency shift) at the lower band and 4.53% (1610 MHz frequency shift) at the upper band. All these absorption and sensing qualities of the proposed MMA with unique shape make it a potential candidate for solid materials sensing in microwave frequency spectrum.

This paper introduces a novel high-gain circularly polarized (CP) antenna that utilizes a NRZI (Near Zero Refractive Index) and MNG (Mu Negative) metamaterial slab. The antenna employs a substrate integrated waveguide (SIW) technique and loaded with compact square split ring resonator (SSRR) combined with a hexagonal-shaped structure by a 0.2 mm width slab as a unit cell to achieve high gain and circular polarization. The metamaterial characteristics were examined through material wave propagation in two main directions at the y and x-axis. For wave propagation at the y-axis, the MTM structure demonstrates mu-near-zero (MNZ) with more than 88 GHz bandwidth, NZRI, and Epsilon-Near-Zero (ENZ) properties. However, for x-axis wave propagation, it indicates a wide negative range of single mu metamaterial from 176 to 220 GHz, NZRI, and ENZ properties. By using six unit cells, the antenna acts as an aperture-efficient focusing metasurface lens and polarization converter for a primary source antenna. The NRZI-MNG enhances the gain of the suggested antenna by 6–7 dB, and converts the linearly polarized wave emitted by the patch antenna into circularly polarized waves. The designed antenna has an impedance bandwidth from 176.5 to 285 GHz, with a 3 dB axial ratio achieved from 177 to 204 GHz. The peak gain of the antenna is 11.3 dBi at 223 GHz, and a gain of around 10 dBi is achieved over the entire CP bandwidth with a good cross-polarization level. In addition, the transmittance of the suggested metamaterial antenna is between 80% and 90% in the operating band. These excellent performances make this antenna very promising for sub-THz 6G applications.

This paper focuses on the evolution of cellular networks as part of their adaptation to the IoT, allowing their new belonging to the category of LPWAN networks. We will be more particularly interested in coverage extension mechanisms. The transmission chain used in this work based on GMSK scheme with maximum likelihood criterion for phase detection. During the theoretical study on the IQ-Prefilter mixed recombination mechanism, we determined an approximation expression of the mean SINR of the frame after recombination. This study allowed us to observe the impact of the temporal correlation of the propagation channel on the performance of the proposed mechanism. A TU6 (Typical Urban 6 paths) channel model will be used in this work. This model is adapted to the urban environment, in accordance with our study on the IoT and the smart city. The effect of the parameters introduced in the theoretical part such as recombination ratio, number of repetitions and duration between each repetition will be evaluated particularly regarding SINR and BER. Based on simulation, the performance of the proposed IQ-Prefilter mechanism is better than those of the IQ and Prefilter recombination for equivalent SNRs. Moreover, the performance of the IQ-Prefilter mechanism is better for low IQ-Prefilter ratios, that is to say when recombination by Prefilter is preferred to recombination by IQ. All the theoretical results and those obtained by simulation make it possible to better evaluate the performance of the suggested mechanisms in the IoT framework.

In the original publication of the article, the affiliation indicators were incorrectly assigned. This has been corrected with this Correction. The original article has been corrected.

A small size neutralization line integrated flower-shaped MIMO antenna is designed and analyzed for sub-6 GHz type 5G NR frequency bands like n79 (4400–5000 MHz), n78 (3300–3800 MHz), n77 (3300–4200 MHz), and WLAN (5150–5825 MHz) applications. The novel approach of theory of characteristic mode analysis (TCMA) is introduced to provide physical insight of the designed structure and its characteristics behavior. Due to the suggested modifications in the geometry, the isolation among the patches is greatly increased. The overall miniaturized dimension of the MIMO antenna is 25 × 40 mm2. The edge-edge spacing among the elements is 0.0233λ. The prototype antenna is fabricated and measured that shows good agreement compared with simulated results. The designed MIMO antenna without the presence of decoupling structure offers an isolation of 28 dB, gain of 3.6 dBi, and radiation efficiency of 69.7% at the resonant frequency. The proposed MIMO antenna covers a broad range of frequency band from 3.296 to 5.962 GHz with −10 dB impedance bandwidth of 2666 MHz and maintains a good isolation of greater than 50 dB for the entire operating band. The tested radiation efficiency and gain are 85.3% and 6.22 dBi at 3.5 GHz. Moreover, the diversity parameters of the neutralization line integrated MIMO antenna, that is, channel capacity loss (CCL) isolation, mean effective gain (MEG), total active reflection coefficient (TARC) diversity gain (DG), and envelope correlation coefficient (ECC), are analyzed and discussed in this article.

This paper investigates a nano-scaled patch antenna in optical frequency range. The proposed nanoantenna consists of a circular patch of dimension 130 × 130 nm2, placed on a glass substrate with thickness 112 nm. To protect the antenna against environmental jeopardies, a superstrate layer of dimensions 40 × 2.5 × 110.4 nm3 has been added. To enhance the performance of the antenna in terms of bandwidth and efficiency and to obtain circular polarization, multiple slots are added into the patch and ground plane of the proposed nanoantenna. The suggested antenna resonates at 182 THz with an impedance bandwidth of about 47 THz (160–207 THz) and a minimum radiation efficiency of 96.54% throughout the entire operating band. The operating bandwidth of the designed nano antenna corresponds to a wavelength range of 1449–1875 nm which covers the entire wavelength of the third optical communication window centered at 1550 nm. Besides, the proposed antenna is circularly polarized which make it very interesting in wireless communication system because it has the advantage to emit the electromagnetic radiation in a corkscrew fashion which allows efficient transmission to the receiver. The proposed antenna covers the telecom optical communication wavelength bands, S-band (1460–1530 nm), C-band (1530–1565 nm), and L-band (1565-1625 nm) in the operating range of 160 THz–207 THz. The proposed nanoantenna with circular polarization might be useful for various integrated components and variety of applications such as optical communication, nano photonics, biosensing, and spectroscopy and could play an essential role in progress of plasmonic sensors.

An offset fed split ring resonator (SRR) based compact printed antenna is analyzed for Ultrawide-band (UWB) applications. The suggested antenna has been designed and analyzed using High frequency structure simulator (HFSS) on a low-cost FR-4 substrate. The top plane of the designed antenna consists of circle and semicircle combined split ring resonator (SRR). The partial rectangular ground along with a semicircular slot is introduced on the back side of the substrate for impedance matching improvement in all over the wide range of frequencies. The offset feed is used for the adjustment of radiation pattern. The fabricated antenna prototype is realized and experimentally tested to authenticate the results obtained from simulation study. This proposed antenna covers the UWB range extending from 3.8 GHz to 14.9 GHz. The proposed compact antenna dimension is 18 × 20 × 1.6 mm3. The proposed antenna achieved a maximum gain of 15 dB at 3.8 GHz. It maintains stable radiation patterns across the operating band. Hence, the obtained results and compact size of the proposed antenna is ideally suited for various wireless applications including wireless local area network (WLAN), Internet of things (IOT), X-band satellite communication, and UWB systems.

A compact co-planar waveguide (CPW) based triple-band printed conformal antenna for on-body applications is presented in this research. In order to accomplish impedance matching, a coplanar structure is employed with the ground on the same plane, and this is printed on the top layer of a polyimide substrate of 0.6 mm thickness. The proposed conformal antenna consists of two identical patch elements. The radiating element is made up of two split ring resonators positioned on the top of the feeding element. The suggested on-body antenna has an overall miniaturized size of only 35 × 37.5 mm2, making it ideal for use in the biomedical field. The designed antenna is capable to cover various spectrum spanning from 2.387-2.618 GHz, 4.2-4.64 GHz, and 6.23-6.56 GHz with a 2:1 voltage standing wave ratio. The designed antenna is fabricated and antenna parameters are measured which is correlated with simulated results. The antenna achieves a total gain of around 5 dBi with radiation efficiency of up to 95 % over the various operating spectrums. To validate the conformality over curved surfaces, the fabricated prototype of the proposed antenna is bent at 30°, 45, 90° angles and the measured results are compared with simulation results of the bending analysis. Furthermore, to validate the on-body performance of the antenna Specific Absorption Rate has been calculated through simulation and it is found to be lower than 1 W/Kg over all three bands of spectrums which proves that the proposed bio-medical antenna could be a viable candidate for microwave imaging applications.

The overwhelming demand for high-data-rate applications and low latency, which are prerequisites for multimedia content, are propelling technological advancements toward 5G communication networks. To acquire the intended 5G requirements and further encapsulate many application areas, a number of technologies has been implemented including millimeter waves and multiple input multiple output (MIMO) systems. One of the primary limitations in creating small MIMO antennas is the presence of inter-element mutual coupling. To cope with the non-desired mutual coupling, this work embodies a defected ground structure (DGS) MIMO antenna operating in a millimeter-wave 5G band. The proposed MIMO array antenna comprises four ports with eight identical patches. It has a total surface area of 50x60 mm2, and is printed on FR4 epoxy substrates with a 4.4 dielectric constant. The bandwidth of the presented structure is extended thanks to the incorporation of slots. The simulation results demonstrate a wide bandwidth covering from 26.9 to 29.3 GHz, and that owing to the DGS, the mutual coupling is alleviated. Subsequently, a high level of isolation (greater than-27 dB), and an ultimate peak gain of 5.525 dBi are reached over the resonance bandwidth. Moreover, investigation of the MIMO diversity performance shows the following parameters: the envelope correlation coefficient (ECC) < 0.0003, diversity gain (DG) > 9.999 dB, and the total active reflection coefficient (TARC) <-10 dB in the operating band. Additionally, the antenna is found to cover the band allocated to 5G in both USA (27.5-28.35 GHz) and Japan (27.5-28.28 GHz). Based on the obtained results, the proposed MIMO array antenna is useful for application in both 5G band handsets and future IoT applications.

This paper deals with the design, simulation, and practical modeling of metamaterial-based multiband conformal bandpass filter (BPF) for various wireless communication applications with improved quality factors. The novel metamaterial in the form of a split ring resonator is loaded on the ground plane face of the proposed BPF. The overall dimension of the designed BPF is only 28 × 28 mm2. The proposed BPF is tuned initially for quality factor enhancement based on the thickness of the substrate, physical parameters of the f transmission line, ground plane, externally loaded elements, and the gap in the metamaterial loading. The suggested filter operates at triple band covering the frequency bands from 1.4 to 2.2, 3.6 to 3.9, and 4.8 to 5.9 GHz, which are suitable for sub-6 GHz 5G and other wireless applications. The insertion loss is observed as 1 dB, which is suitable for the proposed BPF. The conformal behavior of the filter is judged through bending deformation analysis at various bending positions like (15◦, 30◦, 45◦, 60◦, and 90◦). The proposed BPF retains triple pass band characteristics at various bending deformations, which makes it suitable to be used in curved structures or flexible circuitry. The theory of equivalent circuits and quality factor (Q) of the designed BPF is discussed in this paper. The results are analyzed experimentally through ANRITSUMS2037C combinational analyzer. The proposed BPF is suitable for sub-6 GHz 5G, WLAN, and Wi-Max applications.

The emergence of 5G technology is expected to significantly impact high-bandwidth wireless applications, making efficient antenna designs essential. This research paper presents an equivalent circuit for a squareslotted patch antenna design for 5G cellular applications. Indeed, the equivalent circuit for an antenna can be represented by a simple circuit model, such as a resonant LC circuit or a transmission line model. These models can be used to determine the resonance frequency, bandwidth, and radiation pattern of the antenna. Matching networks can also be designed using the equivalent circuit to match the antenna and receiver impedances. This analysis of the antenna can offer valuable insights into its behavior, serving as a foundation for a more extensive investigation. The antenna has been designed and simulated on an FR4 substrate featuring a relative permittivity εr of 4.3, and it is sized at 4.5 × 5.2 × 0.3 mm3. In the proposed design, a 50Ω microstrip line feeds a square-slotted radiating patch, and power dividers join the two elements. As part of 5G technology, it is crucial to achieve high bandwidth with reduced losses and improved gains. This study employs AWR and HFSS to simulate and design the square-slotted microstrip patch antenna, and in terms of gain and S11, the results are compared. The proposed design has the potential to contribute to the development of high-performance 5G antenna systems.

A staircase-shaped printed monopole antenna (SPMA) with a partial ground structure for wireless applications is proposed. The performance parameters of the designed antenna have been evaluated by integrating a novel structure of frequency selective surface (FSS) with the antenna. A Polyimide dielectric material has been utilized for designing both the antenna and the FSS reflector. The proposed SPMA integrated with designed FSS reflector operates at dual bands from 2.18 to 2.83 GHz and 4.42 to 5.58 GHz with fractional impedance bandwidth of 25.94% and 23.2%, respectively. A single-layered FSS reflector with a 5×5 array size is employed to obtain optimum performance. The suggested combined structure of the FSS reflector integrated staircase antenna achieves an attractive peak gain of 7.87 dBi and radiation efficiency of 98.8%. The design methodology for the antenna and unit cell design of the required FSS, analysis of field and current distributions, fabricated prototyped models of antenna and FSS along with measured results are included and discussed in this article. The proposed antenna is suitable for modern wireless communication (WLAN/Wi-Fi etc.) applications at 2.4/5.2 GHz.

Free Space Optical (FSO) communication is a method of transmitting data using modulated light waves through free space, such as air or vacuum, instead of using traditional wired or fiber-optic cables. FSO systems typically use lasers or light-emitting diodes (LEDs) as light sources to transmit data, and photodiodes or other light detectors to receive the data. In this paper, we investigate the error performance of a Free Space Optical system using various modulation techniques under different intensity fluctuation conditions. Our analysis takes into account the combined effects of atmospheric turbulence-induced fading and misalignment fading on the propagating signal. We derive novel closed-form expressions for the statistics of the random attenuation of the propagation channel for each modulation scheme used. Additionally, we perform a comparative study of bit-error rate (BER) performance for all modulation techniques considered in this work. We present numerical results to evaluate the error performance of all modulation schemes used in FSO systems with the presence of atmospheric turbulence and/or misalignment. Furthermore, we compare the OOK, PPM, DPSK, and BSPK modulation techniques to determine the best modulation that achieves the minimum BER for a given signal-to-noise ratio value equal to 30 dB in different scenarios.

Free space optical communication is a technology that uses optical signals to transmit data between transmitters and receivers. In this paper, we analyze the performance of optical wireless transmission using heterodyne binary phase-shift keying (BPSK) modulation. The system is operating under various atmospheric channel effects. More precisely, the combined effects of atmospheric turbulence and fog. Atmospheric turbulence induces intensity fluctuations, and fog causes losses in signal power. To evaluate the optical wireless performances, we derived a mathematical expression of the bit error rate (BER) that combines fog attenuation and turbulence fading. We used a gamma-gamma distribution for modeling atmospheric turbulence fading and Meijer’s G-function for approximating complex calculus. We carried out numerical simulations of the bit error rate for different link distances, Rytov variances, and transmitted powers. The results show that the effects of turbulence and fog are very important for strong turbulence, and these effects limit link transmission. According to the simulation results, it is clear that we can decrease the BER and increase the link communication by raising transmitted power.

A new array antenna is proposed for mm-Wave 5G wireless communication applications in this paper. The array antenna geometry presented consists of six identical patch pieces coupled in a 1 × 6 arrangement with a partial ground plane. To achieve the necessary operating band and high gain range, the structures of each single antenna element are changed by adding combinations of rectangle and triangle-shaped slots with a partial ground plane. The suggested array antenna design and simulation studies were carried out utilizing high frequency structure simulator (HFSS) software. This paper represents how the performance of a parallel feed array antenna changes as the substrate material changes for that we use FR4, Rogers RO3010, and Rogers RT/duroid6010/6010LM substrates with 0.8 mm thickness. The 1 × 6 array antenna FR4 resonates at 38.8 GHz with a bandwidth of 4.2 GHz for the Rogers RO3010 substrate resonates at 37.3 GHz and 40.2 GHz with a bandwidth of 2.8 GHz and 2.7 GHz, and for Rogers RT/duroid 6010/6010LM resonates at 37.3 GHz and 40.6 GHz bandwidth of 2.6 GHz and 2.5 GHz, respectively.

In this article, we focus on Artificial Intelligence (AI) as a teaching topic. At the moment, it is important that every citizen is not a simple consumer of technology. We have challenges to overcome around digital sciences which must have the same place as life and earth sciences in the training of an individual in school curricula. Artificial intelligence is particularly concerned. How to overcome the initial representations of students who may think that these little machines work like magic. It is crucial that students can understand how these voices can inform us about time. The school has a big role to play. As for the teaching and learning of programming which has experienced an exceptional boom in recent years, the idea is not to make young people trained at the school of computer engineers. Rather, it is a question of fully preparing them for the world of tomorrow and understanding what AI is by asking these crucial questions. Beyond the learning mode (individual and / or collaborative), the modeling of user profiles and educational resources of a training domain represent essential parameters for the realization of adaptation to a user in order to recommend relevant educational resources and more finely customize a learning path for a single user in individual mode, but also for a group of users during the synchronization of events in collaborative mode. In this article, after an overview of the existing AI in education, we propose an architecture for the management of this type of adaptive learning.

Faced of the growing demand for wireless multimedia applications, the world of telecommunications today has to respond to a real need for very high-speed radio systems. Among the recent innovations in this field, scientific research in telecom is particularly interested in the Terahertz frequency range which consists in using frequency bands of the order of 300 GHz to a few THz. This large frequency spread gives the terahertz frequency band unique characteristics, such as its high temporal resolving power and its low absorption. A wireless network allows two or more devices to communicate by radio link thanks to the propagation of electromagnetic waves. Setting up a wireless network usually involves finding strategies and ways to meet the many demands of users. Among which the transmission rate and the reliability of the communications, the mobility of the users and the low cost of the equipment. Indeed, the operation of these networks is more or less disturbed by many sources of distortions linked in particular to the propagation of waves in the real environment and to the intrinsic defects of the electronic components put in place in the Radio chain.

This paper introduces a new 4-port multiple-input multiple-output (MIMO) antenna for future 5G applications. The proposed MIMO antenna is formed of 4 identical hexagonal patches, and each patch is hexagonally slotted to achieve the desired results. The ground plane of the antenna is made up of 4 similar rectangles, each with a size of 15 × 22 mm2. The substrate of the antenna is made using FR4-epoxy which has a dielectric constant of 4.4 and a thickness of 1.08 mm. The proposed MIMO antenna has dimensions of 50× 55× 1.08 mm3. The suggested antenna has been simulated and analyzed using the high-frequency structure simulator (HFSS). The suggested antenna resonates from 23.4 to 27.6 GHz with a wide bandwidth of 4.14 GHz and a return loss of about −43.50 dB. Furthermore, the antenna offers a high isolation which is largely sufficient for 5G future applications. The suggested MIMO antenna covers the European band (24.25–27.50 GHz) that has been widely used since 2020. All the captured results in terms of return loss, isolation, and other parameters and also the compact size of the antenna prove that the proposed MIMO antenna can be of a great use for 5G applications.

The diagnosis of diabetes requires many physical and chemical tests, as well as many other tests, although untreated and undiagnosed diabetes causes the destruction of body organs such as the eyes, heart, kidneys, feet, and nerves and may result in loss of life. Therefore, early detection and analysis of diabetes can help reduce mortality rates. In this paper, we develop accurate machine learning models for detecting diabetes. These models are based on three algorithms: the first is Logistic Regression (LR), the second is Support Vector Machine (SVM) and the third is Random Forest Classifier (RFC). They are performed on Diabetes data known as PIDD, which is obtained from the website Kaggle. Thereafter, the performance of predictive models is evaluated using accuracy, sensitivity, and F1 score measures. The model based on predictive learning of random forests emerged as one of the best performing models with 0.96 accuracy, 0.99 sensitivity, and 0.97 F1-score.

The aim of this paper is to reduce the ‘‘BER’’ and the difference between the two LDPC code families: the hard and soft one, for that, a novel hybrid “LDPC” decoding algorithm is proposed, which mixed the “Normalized Min-Sum” (NMS) and “Single Noisy Gradient Descent Bit flipping” (SNGDBF) that belongs to the soft and hard decision decoding. “The Normalized Gradient Min Sum” algorithm is proposed in this paper (NGMS). The proposed algorithm gives good results in terms of correction power, it surpasses the other algorithms with a considerable gain margins at 10–5 over the “Additive White Gaussian Noise” (AWGN) channel, according to the simulations. In addition, the suggested “NGMS” and “NMS” have the same level of decoding complexity.

Artificial intelligence is the set of information processing technologies aimed at conferring cognitive abilities comparable to that of humans to computers, machines or robots, through mathematical functions, algorithms but also modes of representation of the real environment. There are generally two main approaches in AI: symbolist approaches, where knowledge and reasoning are represented by a mathematical formulation or logic (with symbols) and connectionist approaches, where cognitive function is achieved by assembling formal, mathematical neurons, connected to each other in more or less complex networks (neural networks). Faced with the difficulties encountered by symbolist approaches to formalize robust reasoning in a real world with many exceptions, and also thanks to the opportunity represented by accumulated data (big data), learning cognitive functions from data becomes a promising option. This is the whole point of machine learning. In this research work, we are mainly interested in the methods of machine learning. A practical case will be discussed in this paper.

Given the fact that the network in some regions is weak, this paper aimed at realizing a 5G network booster circuit. To achieve this objective, we suggested resolving this shortage by adopting an adequate circuit in which we implemented different types of antennas in numerous iterations to increase the network strength and reduce the response time. The core of this idea is a simple scheme that makes use of two helical antennas. The first one is excited by the mobile phone while the second is induced. Unwanted noises decrease and the signal (magnetic field) strength at the output of the system are obtained by the stability of the circuit due to the good polarization of the transistor, its functioning in a narrow band of high frequencies, and the best selection of coupling capacitors. The major finding of our study is that the use of a strong magnetic field would help improve the quality of the network. This has been done to ensure good transmission of data among devices, especially those using 5G. Lots of features, then, are enhanced, namely directivity, gain, and selectivity.

Unlike other mobile network technologies, 5G is a disruptive technology. Because 5G can address not only the general public but also major economic sectors for B2B (Business to Business) uses. So that, the implementation of 5G system is harsh task. Antenna is one of the important element to implement 5G technology. In this regard, this paper deals with the design of defected ground structure Multiple Input Multiple Output (MIMO) antenna functioning in the millimeter-wave 5G band for the future IoT applications. The proposed MIMO antenna consists of four MIMO elements with eight identical patches and it was derived after multiple iterations. The bandwidth of the proposed antenna is about 2.5 GHz ranging from 26.8 GHz to 29.3GHz. This high bandwidth is obtained by the use of slots in the first iteration and defected ground in the final iteration. The MIMO antenna was simulated via HFSS. The study’s major findings are as follows: First, the proposed antenna covers the band allocated to 5G in USA 27.5–28.35 GHz and Japan (27.5–28.28 GHz). The second finding is lower isolation less than −35 dB which mean the coupling between antenna can be ignored. Finally, the peak gain at the operating band is about 18.25dBi. The above-mentioned results made the MIMO antenna that covers 27.9 GHz (26.8–29.3 GHz) useful in 5G band handsets.

MIMO (Multi-Input Multi-Output) systems have become one of the most studied topics in research because of its ability to increase the spectral efficiency (capacity) over a limited bandwidth. The use of multiple antennas leads to an additional dimension in the degree of multiple access to the network compared to the single-antenna case and thus offers an effective solution to increasing data rates for future generations of cellular radiotelephony. In this paper, a 2 × 6 MIMO antenna array structure is presented. HFSS software is used in the simulation process of the designed antenna. The proposed structure covers the frequency band ranging from 1.2 to 6.3 GHz. A thin Rogers 5880 RT substrate of 54 × 60 × 0.4 mm3 is used to design the antenna. The behavior of the MIMO antenna has been studied as a function of a certain number of parameters, namely: the distance separated MIMO antenna elements and the radius of the slot in the patch. The results show that the variation of these parameters affects the isolation. The design of the proposed antenna is done, by fixing the distance at λ/2 and the radius at 2.25 mm, in such a manner we get a high isolation between the radiating elements of about – 83.8 dB which will provide a reliable anti-interference performance for the system. The outcomes make this antenna a potential candidate for 5G application at the sub 6 GHz band

Designed for increased speed and capacity, 5G has the potential to significantly expand the way the data will be processed and transported, and will allow a wide range of new use cases, which go far beyond the smartphone, already targeted by the 3G and 4G technologies. The present paper focused on the development of new antenna technologies for millimeter waves 5G communications. In this direction, a new two-ports Multiple Input Multiple Output (MIMO) antenna functioning in the mm-wave band is proposed in this paper to support 5G communications at 38 GHz. The proposed MIMO configuration has a size of 43 × 25 mm2 is printed on FR4 substrate material with a 0.8 mm thickness, a dielectric loss tangent of 0.02 and a relative permittivity of 4.4. By incorporating combinations of rectangular and triangular shaped slots into the patch elements and a partial ground plane with a rectangular slot, the desired band operation is achieved with enhanced gain and bandwidth. The considered antenna in this paper has a bandwidth of 3.38 GHz (36.8 GHz 40.18 GHz) in the desired band of 5G applications with isolation less than – 24 dB and peak gains of 4.85 dBi at 38.5 GHz. The proposed MIMO antenna covers many countries band like UK (37-40), USA (37-37.6), Canada (37.6-40.0) and Australia (39 GHz)

For several years, the fields of new technologies have been experiencing a real boom. The use of the terahertz band is an appropriate solution to meet the requirements of these technology. However, this technology has special requirements among which its antennas must have high bandwidth of few THz and achieve high gain for high productivity. In this paper, we will focus on the design and analysis of an antenna for THz technology. The antenna structure proposed in this work has better performance in terms of bandwidth and gain. In fact, multiples slots were added to the antenna to enhance the antenna’s bandwidth. In addition, to enhance the antenna performance in terms of gain and protect the antenna feed line against environmental jeopardies a thin layer as superstrate is used. The suggested antenna covers a wide −10 dB bandwidth from 0.9 to 17.3 THz with a peak gain of 12.8 dBi. Moreover, a VSWR less than 2 at the operating band is obtained. Furthermore, the suggested antenna has circular polarized radiations with an axial ration (AR) less than 3 dB over a wide band 13.6–17.3 THz which mean that the proposed antenna is well suited for application where the transmitter and receiver are moving which is the most case for wireless system. Thus, the suggested THz antenna could be a successful choice for terahertz application like future high-speed short-range indoor wireless communication, explosive detections, arms detection, medical imaging, pharmaceutical analysis, and material characterization in the THz regime industrial inspections.

The choice of modulation and waveform is a crucial step for generating a radio signal and designing a wireless communication system. Toward this end, a compromise between low-complexity and high-data rate had to be considered when selecting the appropriate transmission technique. Indeed, pulse-based modulation can be a good candidate for THz system due to its simplicity and it supports very high data over short distance. In this work, we proposed a solution based on multiband on–off keying (MB-OOK) modulation using a noncoherent receiver. A deferential MB-OOK transceiver has been evaluated over a THz channel model. A data rate of 54.24 Gbps is achieved with a BER of 10–3 when the distance between transmitter and receiver less than 35 m. Furthermore, the proposed system offers a good compromise between throughput, consumption, and complexity, which allow it to be a good candidate for THz applications.

In this study, we mainly focused on a theoretical analysis of HomePlug 1.0 and an experimental analysis of modem data rates through a section of a PLC network with several configurations. We introduce the utilization of the MIMO technique to increase the throughput over a PLC channel. Besides, we propose a MIMO PLC channel model to evaluate the channel transfer function of MIMO PLC. We used an equivalent per-unit-length model of the indoor power line network to characterize the three-conductor cable. Based on this mathematical model, we analyzed the throughput of the PLC network with different household appliances. The equivalent circuit of each appliance is also given. The simulation results showed that the throughput is influenced by household appliances connected to the sockets of a MIMO PLC network. Moreover, we also compared the throughput between single and multi-antenna systems. Based on the simulation results, we found that the data rate increased with frequency. In addition, the performance of the MIMO PLC system was almost 90% higher than that of a SISO PLC system in terms of channel capacity.

This article presents the design, analysis, and realization of a new printed multiple-input-multiple-output (MIMO) antenna with a very high gain and wide bandwidth for the millimeter-wave (mm-wave) 28/38 GHz fifth generation (5G) new radio (NR) applications. The proposed MIMO antenna consists of four identical patch elements in a 2 × 2 configuration to achieve high gain with wide operating bandwidth. The proposed antenna holds an attractive compact size of 31.891 × 37.528 mm2. The proposed MIMO configuration is designed on a 0.508 mm thick Rogers-5870 substrate material with a loss tangent of 0.0009 and a relative dielectric constant of 2.33. An effective technique for folding the feed line and applying a new protruding ground is introduced to obtain good mutual coupling. The fabricated prototype of the proposed antenna is tested to verify the simulation results for the validation of the suggested design approach. The suggested MIMO antenna exhibits −10 dB impedance bandwidth of 2.6 GHz (27.4–30.0 GHz) and 3.3 GHz (36.7–40.0 GHz) to cover the intended frequency range for 5G applications with isolation less than −22 band peak gains of 18 and 14.5 dBi at 27.5 and 38.8 GHz, respectively. To validate the MIMO performance of the proposed antenna several MIMO diversity parameters such as mean effective gain (MEG), envelope correlation coefficient (ECC), and diversity gain (DG) are evaluated. Determined results indicate ECC < 0.001, DG > 9.995, and an average MEG of −3 dB at the operating bands. The proposed antenna exhibits good agreement between the simulated and measured results, which confirm its suitability for forthcoming mm-wave 5G MIMO systems and services.

A new 4-port dual-band printed Multi-Input Multi-Output (MIMO) antenna array operating at 28 GHz and 38GHzin the mm-wave band for 5G communications is proposed in this paper. The designed MIMO antenna array consists of 4 MIMO elements structured with 8 identical patches arranged in 2 × 4 configuration and a cross-shaped defected ground plane on a physical footprint of 43.611×43.611×0.4mm3 Rogers RT/duroid 5880 substrate. In order to obtain the desired dual-band operation with good impedance matching, enhanced gain and bandwidth, the patch elements are designed by incorporating combinations of circular and semi-circular shaped slots, and the cross-shaped ground plane is modified with an extended circular-shaped defect. The suggested MIMO configuration offers a high gain of about 7.9 and 13.7 dB at 28 and 37.3 GHz, respectively. Furthermore, the MIMO performance metrics of the proposed design are analyzed and presented. The prototype of the designed MIMO antenna has been fabricated and measured to validate the simulation results. The simulation and measurement results show good agreement. The proposed MIMO antenna covers 28 GHz (27.50–28.35 GHz) and 37 GHz (37–37.6 GHz) 5G bands to be deployed in the USA and Canada.

The THz frequencies are the new revolution in the telecommunication due to theirs several advantages this paper will propose a MIMO patch antenna polyimide based that is capable to function at THz frequencies. The performance of the proposed antenna has been analyzed in term of multiple antenna characteristics such as impedance bandwidth (GHz), gain (dB), return loss (dB), and VSWR. The Polyimide substrate having thickness of 9 µm and lower dielectric constant, and εr of 3.5 has been used in the antenna design. The HFSS (High frequency structure simulator) which is based on the finite element method is used to design and simulate the antenna. In this work, we present the results of a parametric study of a MIMO 2 × 2 patch antenna in the frequency band Terahertz (THz) ranging from 2.526 to 2.995 THz (a bandwidth of 469 GHz) and has a reflection coefficient of about - 21.44 and -29.62 dB and a gain of 6.67 dB at 2.74 THz.

Over time, scientists and engineers exploited the frequency bands of the electromagnetic spectrum. Starting with the visible spectrum, they gradually developed sources and detectors operating at lower and higher frequencies. First, the frequency band between 0.1 and 30 THz, called terahertz (THz), has not been fully exploited. On the other hand, with the current development of communication and broadband, many parts of the electromagnetic spectrum are saturated. For this, scientists are interested in the terahertz (THz) domain, which, thanks to its high frequencies, offers the possibility of increasing the data rate. Indeed, the transmission of bit rates of the order of one Tbit/s is potentially possible with THz waves, which is advantageous for a wireless communication technology. However, the main difficulty with its use is the lack of compact, powerful, and inexpensive sources and detectors. The objective of this work is to set up detectors that can be used in the THz field. In this chapter, we will begin by describing the terahertz (THz) spectral domain and the applications exploiting this frequency band.We will also list some detectors that currently exist on the market. THz detection methods with equivalent sampling by photoconductive antennas, by electro-optical sampling, and by plasma in air are discussed here. In addition, spectral domain interferometry (SDI) and bolometer detection systems are discussed later in this chapter.

This book presents scientific and technological innovations and advancements already developed or under development in academia, industry, and research communities. It includes fundamental ideas and advancement in terahertz technology covering high intensity terahertz wave generation, THz detection, different modes of THz wave generation, THz modulation system, and terahertz propagation channel modeling. It highlights methodologies for the design of terahertz components and system technologies including emerging applications. The chapter contents are based on theoretical, methodological, well-established, and validated empirical work dealing with different topics in the terahertz domain. The book covers a very broad audience ranging from basic sciences to experts and learners in engineering and technology. It would be a good reference for advanced ideas and concepts in THz technology which will best suit microwave, biomedical, and electrical and communication engineers working towards next-generation technology.

To determine the performance of a wireless system, channel characterization must be carried out. In fact, in a wireless system, the propagation of an electromagnetic wave in space is of particular importance. For this reason, it is necessary to study the correctness of this channel before starting to work on it and implementing it in a communication system. It is therefore essential to have knowledge of the mechanisms involved in the propagation channel and of its interactions with the environment in order to be able to predict the chances and conditions for establishing a radio link between a transmitter and a receiver. In this work, we propose some strategies to model the transmission channel in the THz band. Indeed, before we can evaluate a transition system over wireless system, we have to model the propagation channel. First, we present the main tools allowing the modelling of the channel in the THz frequency range, which is considered a key new technology to meet the growing demand for higher speed wireless communications, as well as its impact on radio systems. In this paper, we propose a channel model for a wireless system working in the THz band. Besides, we propose some strategies to model the entire system as well as the propagation channel. We also simulate the proposed channel model. The simulation results show that the proposed system can be considered as an example for evaluating the performance of a communication chain based on a wireless system in the THz bands.

This research presents a flower-shaped design of a multi-input multi-output (MIMO) antenna with dual wide operating bands in the millimeter-wave (MMW) region proposed for 5G applications. The antenna system consists of a quad-port antenna array placed with a 90-degree shift; it was etched on a low-cost FR-4 dielectric substrate with a full size of 22×22×1 mm3. The objective of this work it to enhance the bandwidth of the proposed MIMO antenna as well as to increase the antenna gain. To increase the gain, we used multiple single antennas and to enhance the bandwidth we added some slots to the suggested antennas. The array antennas are designed to provide dual-band operation at the frequencies of 29 GHz (n257) and 39 GHz (n259). The results are simulated using HFSS, acceptable gain reaches 3.04 dB and 8.11 dB in the first and second bands, respectively, while the impedance bandwidth achieved by the design is about 1600 MHz (28.9-30.5 GHz) at 29.8 GHz and about 2330 MHz (38.43-40.76 GHz) at 39.6 GHz with a reflection coefficient S11 of about – 16.20 dB and – 19.27 dB, respectively. The proposed antenna can be a desire choice for 5G applications because of its low cost, small size, high performance in terms of bandwidth and gain.

Interest in terahertz (THz) technology is related to various applications such as object detection, spectroscopy, security, and telecommunications. However, one of the challenges of THz technology is the implementation of effective communication between the transmitter and the receiver. Modulation technique like orthogonal frequency division multiplexing (OFDM) is already used in the THz band. However, the most widely used transmission method, on-off keying (OOK) scheme, presents several problems in highrate data detection. In fact, the purpose of this work is to design in Matlab Simulink a transmission chain based on the energy detector, frequently used for transmitting radio pulses, since applications focused on the ultra-wide band are much less complex to implement and consume little power. In this regard, we present a delay-modified energy detector that will allow the sample to optimally select the maximum energy levels corresponding to the sending of logical bit 1 and logic bit 0. And we have chosen an energy detector with OOK modulation in the additive white Gaussian noise (AWGN) channel. The proposed system has a low cost, high performance and low power consumption, so it can be effectively used for a THz system.

THz channel is a multipath channel that causes large differences between transmitted and received signals. To do transmission over this environment, the channel model must be realized. In fact, modeling the THz channel will allow researchers to develop the THz communication system, as well as to establish an effective communication algorithm, which could improve the data transmission. In this work, we derived mathematical expressions defining an analytical model of the THz MIMO channel based on correlation. Moreover, we focused on the knowledge and modeling of the THz MIMO propagation channel in order to develop suitable tools when analyzing the performance of a MIMO transmission chain. Simulations of the transfer function and impulse response have been carried out in order to validate the proposed model.

Multipath channels cause large differences between transmitted and received signals. These variations depend on time, frequency and space. Since we cannot act on the transmission channel, it becomes a drawback for signal transmission. So, the interest in characterizing and modeling the transmission channel takes on its full meaning. Modeling a channel enables us to design, validate and test a technology, as well as to establish an effective communication algorithm, which could optimize the transfer of information. Simulations of CDF (cumulative distribution function) have been carried out in order to validate the proposed model.

A compact offset microstrip line-fed printed multiband monopole antenna is proposed. In this work, the suggested antenna operates at multiple resonant frequencies due to the incorporation of narrow parallel slits and a hammer-shaped slot on the radiating patch with a modified ground plane. The proposed antenna has been configured on a 26 × 25 mm2 FR-4 substrate (εr= 4.4 and thickness = 1.6 mm). The simulated return loss results confirm the penta-band resonances from 2.9 to 3.2 GHz, 3.22 to 3.65 GHz, 5.6 to 6.5 GHz, 7.8–8.4 GHz, and 9.4–11.1 GHz to support multi-standard wireless systems such as maritime radio navigation, Wi-MAX, WLAN, X-band satellite communication uplink, ITU band, and aeronautical radio navigation bands. The simulated antenna parameters such as VSWR, radiation pattern, gain and directivity along with surface current distribution have been analyzed in detail and presented in this article. The designed structure maintains VSWR < 2 within the operating penta-bands which indicates very low mismatch losses in the design consideration. Furthermore, almost stable radiation patterns are obtained at all the operating frequencies. Simulated maximum peak gain of about 3.43 dBi at 5.8 GHz is reported for the proposed design.

Wireless communications require more and more communication speed. One solution to meet this growing demand is the use of the millimeter band. In fact, it has been already shown that a system operating in millimeter bands offers communication speeds of several gigabits. This drew the attention of researchers to work on the THz band. This made this band a candidate for future 5G communications systems. However, the major drawback remains a severe attenuation due to the absorption of oxygen. Certain studies carried out to characterize the THz channel propose the use of directional antennas to compensate for the attenuation of the propagation effect. In this work, we will propose the MIMO-OFDM technology, which allows converting the THz channel into several flat fading subchannels and at the same time increase the transmission rate. In the present work, we present the performance of the MIMO-OFDM communication system operating in the THz band. The performance of the MIMO-OFDM system has been studied in terms of BER. In order to evaluate the performance of our system, the THz channel has been modeled.

In wireless communication systems, the transmission channel constitutes the medium separating the transmitter from the receiver. Due to the growing demand for wireless systems in terms of data rate, it is necessary to look for new technology to support this need. Nowadays, The interest of Terahertz (THz) technology is growing increasingly. Indeed, THz technology indeed has the potential to provide ultra-fast data rate of Terabit-per-second (Tbps), Reliable Low Latency Communications and multimedia applications for wireless communication systems. However, the transmission channel at Terahertz bands poses more complexity than the currently used sub-30 GHz bands. The increase in the carrier frequency led to a high path loss. In this direction, Constant envelope Orthogonal Frequency Division Multiplexing (CE-OFMD) modulation is used in this work to increase the quality of transmission in terms of the Bit Error Rate (BER). Thus, In order to develop the THz system and effectively exploit the advantages of this technology, it is essential to know the properties of the radio channel in THz Band than to implement the THz channel in the transmission chain based on CE-OFDM. To do that, an accurate model for THz channel have to be expected by taking into account the effect of both the scattering loss and atmospheric attenuation which are the main characteristics of THz channels. The proposed model in this chapter is based on the Saleh-Valenzuela (S-V) statistical model which combines the concepts of “clusters” and AOA (Angle Of Arrival). In order to validate the proposed model, simulations of frequency channel response and time domain channel are carried out. It has been demonstrated from simulation that the performance of the THz system depends on the transmission windows. For this reason, we used CE-OFDM over these transmission windows to improve the performance of THz system.

Terahertz (THz) antennas are achievements benefit in many applications. The interest of THz technology has been growing steadily since the creation of Terahertz Interest Group in 2008. By its unique characteristics, THz technology indeed has the potential to provide very high-data rate for wireless communication system. However, the atmospheric absorption presents in THz communication system cause high path losses. Using high gain antennas can compensate the increased path loss. Indeed, antennas are the most essential part of any wireless communication system. Thus, antenna designs for THz bands create new challenges for the researchers. In fact, the design of very high gain, directive and wideband THz antenna is very challenging and promising tasks. In this chapter, we present some advantages of antennas for THz radio communication system. Firstly, we expose the fundamental principles of the theory of antennas as well that the general characteristics of the antenna systems realized with a certain number of radiators. We will analyze antenna’s systems by studying their characteristics. Steps for designing an antenna will be given. All this information may guide the user in choosing the configuration that will best respond his needs. A single-element antenna with new geometry is proposed in this contribution. The proposed microsrip slot antenna with defected ground having a circle shaped fractal and comprise a microstrip with corporate feed network operating at 5 THz which is considered as Terahertz band. The proposed antenna has the highest bandwidth of about 12.2 THz (3.6–15.8 THz) with a gain of 5.6 dBi. The designing and simulation are performed using High-Frequency Structure Simulator (HFSS). The simulation output shows a high bandwidth, enhanced gain and minimum VSWR (Voltage Standing Wave Ratio) value at THz band, which would be an excellent candidate for THz wireless communication.

A single band printed antenna with a modified E-shaped structure is proposed for 5G applications at 28 GHz band. The suggested antenna has been constructed on a 5.5 × 4.35 mm2 FR-4 substrate (εr= 4.4 and h= 1.6 mm ) through slot loading technique. The incorporation of rectangular and tiny square shaped slots has improved the resonance and radiation characteristics of the designed antenna. The wide operating bandwidth of the suggested antenna covers 25.99–29.88 GHz frequency spectrum to support 28 GHz 5G applications. The presented antenna depicts low mismatch loss and thus better impedance matching offering a reflection coefficient of about −40.88 dB at 28 GHz. The proposed antenna offers desired radiation patterns (E and H planes) with a peak gain of about 5.64 dBi at 28 GHz. Furthermore, an extensive analysis of VSWR, input impedance, and surface current distribution are also presented to explain the working functionality of the suggested antenna. The proposed structure is a preferable choice for 28 GHz 5G applications due to its compact size and high performance parameters and it covers the bandwidth requirements of 5G applications at 28 GHz.

The 5th generation (5G) Network technology must meet various stringent necessities such as high spectral efficiency, low energy consumption and immense connectivity. Current wireless communication system uses radio resources to transmit data with Orthogonal Multiple Access (OMA). But, as the number of user’s growths, OMA-based technique might not meet user requirements. That why, NOMA has been introduced to fulfil the challenges of 5G network. This article provides a comparison between NOMA and OMA systems. The main NOMA strategies are debated by dividing them into two classes, namely, the power domain and the NOMA code domain. In addition, benefits and limitations are discussed.

In the present work, we propose a novel modulation scheme for 5G wireless communication system. Our contribution is to combine PM-OFDM (Phase Modulation Orthogonal Frequency Division Multiplexing) and CDMA (Code Division Multiple Access) to exploit their distinctive advantages. On the one hand, PM-OFDM is an effective technique to combat multipath fading effects. On the other hand, CDMA can serve multiple users who are using the same resources of time/frequency. The aim is to make a combination of PM-OFDM and CDMA techniques. In this paper, the OFDM-CDMA scheme and its PAPR (Peak-to-Average Power Ratio) statistics are reviewed. In this paper, the proposed scheme PM-OFDM-CDMA is described and its performances in terms of PAPR, power spectral density, and BER (Bit Error Rate) are analyzed. Moreover, MMSE (Minimum Mean Square Error) equalizer is used to avoid multipath and noise effects simultaneously. The simulation through AWGN (Additive white Gaussian noise) and Rayleigh channels is performed using MATLAB. From the simulation results, we observed that PM-OFDM-CDMA is an efficient technique in terms of energy consumption (PAPR = 0dB). Besides, CE-OFDM-CDMA offers high spectral efficiency with low BER due to its low PAPR. In CE-OFDM-CDMA method, the shape of the spectrum varies according to the value of the modulation index h. The band occupied by the spectrum increases with the value of h. Therefore, CE-OFDM-CDMA could be considered as a suitable technique for 5G applications.

A new compact 1×4 microstrip patch antenna array design for future 5G applications is presented in this paper. The proposed antenna array consists of square slot loaded with four radiating patch elements. The corporate feed network has been implemented for the excitation of the array. The feed line is connected to the square slot patch through a quarter-wave transformer matching network. The proposed array is designed on an FR-4 substrate with a dielectric constant of 4.4, thickness of 1.6mm and loss tangent (tanδ) of 0.02. It has a compact dimension of 9.590× 17.802×1.6mm3. The proposed structure has been designed and simulated by using commercially available HFSS software. The simulated results (reflection coefficient, gain, efficiency, radiation pattern) are verified through the measurement process to confirm the validity of the design concept. The measurement results are in good agreement with the simulated results. The proposed structure resonates at 38.1GHz with a -10dB impedance bandwidth of about 3700MHz (36.5GHz to 40.2GHz). The reflection coefficient at 38.1GHz is -34dB, with a maximum gain of 7.81dB. The proposed square slot loaded patch antenna array is very promising for 5G communications at 38GHz band (37-40GHz).

The aim of this work consists in characterizing the Terahertz (THz) propagation channel in an indoor environment, in order to propose a channel model for THz bands. We first described a propagation loss model by taking into account the attenuation of the channel as a function of distance and frequency. The impulse response of the channel is then described by a set of rays, characterized by their amplitude, their delay and their phase. Apart from the frequency selective nature, path loss in THz band is also an others issue associated with THz communication systems. This work based on the conventional Saleh-Valenzuela (SV) model which is intended for indoor scenarios. In this paper, we have introduced random variables as Line of sight (LOS) component, and then merging it with the SV channel model to adopt it to the THz context. From simulation, we noted an important effect when the distance between the transmitter and the receiver change. This effect produces variations in frequency loss. The simulations carried out from this model show that to enhance the performance of THz system it is recommended to transmit information over transmission windows instead over the whole band.

Phase Modulation Orthogonal Frequency Division Multiplexing (PM-OFDM) and Code Division Multiple Access (CDMA) have distinctive advantages. On one hand, PM-OFDM is an attractive technique to combat multipath fading and reduce high PAPR in conventional OFDM. On the other hand, CDMA has the ability to serve multiple users at the same time and/or frequency. In this article, a new PM-OFDM-CDMA system that combines PM-OFDM and CDMA is proposed. The idea behind the proposed technique is to combine the advantages of these techniques in order to enhance the performance of the 5G system by serving multiple users simultaneously. The performance of the proposed system is analysed in terms of BER under different channel conditions. A Minimum Mean Square Equaliser (MMSE) scheme is used in order to avoid the effect of multipath effect and noise simultaneously. From the simulation results, we conclude that the proposed system has good performance that can improve 5G wireless communication networks, especially for battery-powered mobile devices. This amounts to the constant envelope of the proposed waveform which generates constant instantaneous power and therefore reduced PAPR.

Thanks to the development of wireless communication technology, the whole world has become a small village, especially in the last 10 years. In fact, there are several reasons for this revolution, the most important of which is the transition to higher frequencies that would allow high-speed data transmission. In order to reach this high speed, it is necessary to increase the frequency up to ten terahertz (THz). In this case, we are talking about what is called THz wireless communication, the case where the frequency is between 0.1 and 10 THz. Thus, the bandwidth used in this frequency range is wide or ultra-wide. This introduces negative impacts on this communication system, mainly the effect of selective fading in frequency (multiple trips). The appropriate selection of a modulation technique makes it possible to remove these effects. Suitable solutions to this problem include the Oversampled orthogonal frequency division multiplexing (OOFDM) technique. The objective of this work is to improve and optimize the performance of a wireless communication system in the THz frequency band using the OOFDM modulation technique.

The use of electromagnetic waves is a powerful tool for observing and understanding the world around us. From the infinitely large and distant, electromagnetic waves allow us to “see” objects and analyze them through spectroscopy. The tremendous scope of the electromagnetic spectrum multiplies the fields of observation and applications. Far infrared is a specific region of the electromagnetic spectrum with frequencies typically between 0.3 and 20 terahertz (THz). The wavelengths associated with these frequencies range from 1 mm to 15 µm. This domain of the so-called terahertz waves is still little exploited at the technological level. The antenna is one of the most frequently used components for THz generation and detection. It generates and detects THz pulses by transient photocurrents induced by ultra-short excitation laser pulses. In this paper, a rectangular patch antenna having 47.916×37.693μm2 dimension printed on Rogers RT/duriod 6010 substrate is presented and analyzed. The proposed MIMO antenna offers high bandwidth with less return loss. Other antenna parameters were studied in this work such as radiation patterns and current distribution. To have a good picture about the designed antenna we analyzed the isolation of the MIMO antenna. Based on simulation, the proposed antenna can be used efficiently in THz applications.

Terahertz (THz) communication is one of the suitable technologies for the upcoming 5G and 6G standards. In fact, THz frequencies cover the electromagnetic spectrum between 0.1 and 30 THz or 3 mm and 10 µm in wavelength. The limits of this domain started at the confines of radio frequencies and cover the frequent spectrum which extends until the beginning of the infrared domain. These frequencies have the advantage of being non-ionizing given the low energy transported. Furthermore, the use of THz frequency for wireless communication systems increase the data rate over the wireless network. Nevertheless, the multi-path nature of this high bandwidth channel is also a major issue in THz channel. Orthogonal frequency division multiplexing (OFDM) is a strong communication technique that mitigates the effects of THz channel. In this chapter, we investigate the OFDM modulation technique for the THz wireless radio system over multi-path propagation channel. By giving a multi-path channel model for THz communication system, we design a transceiver architecture based on OFDM system to delete interferences at the baseband. Simulations shown that with OFDM modulation the THz communication system can achieve high capacity. In this work, we study the bit error rate (BER) of phase shift keying (PSK) and quadratic amplitude modulation (QAM) constellation in presence of OFDM modulation with a carrier frequency of 300 GHz over THz channel module including LOS and NLOS propagation. It is detected from simulations that the OFDM technique can be a suitable solution for THz communication system.

The first step to design an efficient terahertz (THz) system is to find out suitable waveforms and modulation schemes that can be used in THz wireless system. Towards this end, a compromise between low-complexity and high data-rate had to be considered when selecting the appropriate transmission technique. The purpose of this work is to study the feasibility of THz system at a short distance by means of pulse-based modulation. To do that, a multi-band on-off keying (MB-OOK) transceiver has been presented and analysed under a channel model that considers both line-of-sight (LOS) and non-los (NLOS) components. We examined three approaches named monoband OOK, 4 sub-bands OOK and 8 sub-bands OOK. Simulation results carried out for the three approaches. A data rate of 125.09 Gbps can be supported at 20 m using the 8 sub-bands approach with a bit error rate (BER) less than 10–3.

Fifth generation (5G) wireless technology is a new wireless communication system that must meet different complementary needs: the high data rate for mobile services, low energy consumption and long-range for connected objects, low latency to ensure real-time communication for critical applications and, high spectral efficiency to improve the overall system capacity. The waveforms and associated signal processing present a real challenge in the implementation of each generation of wireless communication networks. Different research works have discussed this topic; but, these works are limited to the Filter-Bank Multi-Carrier (FBMC), Universal Filtered Multi-Carrier (UFMC), and Filtered Orthogonal Frequency-Division Multiplexing (F-OFDM) waveforms. In this work, we review the technical basics of the physical layer for the LTE system which uses, OFDM modulation for the downlink and the single carrier frequency division multiple access (SC-FDMA) technique for the uplink. Besides, this paper presents the diverse waveforms candidate for 5G systems, including, FBMC, UFMC, and F-OFDM, and compares these techniques with Constant Envelope-OFDM (CE-OFDM), which is an advantageous form regarding power consumption, especially for battery-powered devices. Simulations are carried out to compare the performance of the OFDM, CE-OFDM, F-OFDM, UFMC, and FBMC in terms of power spectral density (PSD) and Bit Error Rate (BER). It has been demonstrated that (CE-OFDM) constitutes a more efficient solution in terms of energy consumption than the other technics. By comparison with the other technics, the CE-OFDM scheme performances, in terms of BER and PSD, are controllable by the values of its parameters (M, h, and J). This advantage gives designers of the system to consider the mutual choice between spectral efficiency and the BER. Moreover, the (F-OFDM), (UFMC), and (FBMC) schemes could constitute a more efficient solution in terms of power spectral density. It can be concluded from this paper that CE-OFDM wave form gives the best performance in terms of power consumption by reducing the Peak to Average Power Ratio (PAPR) associated with the OFDM system and FBMC is an efficiency technique to reduce the inter-carrier interference (ICI).

A solution that today interests a good number of industrialists consists in using the most dense and ubiquitous network: the electricity network. Communication over energy line, commonly known as PLC (Power Line Communications), makes it possible to consider a completely different type of electrical local loop. The main advantage of such a network relies to the ubiquity of the infrastructure, both inside an outside buildings, thus, making it possible to considerably limit the costs of network deployment. One of the options chosen to increase throughput on the PLC networks is the use of OFDM (Orthogonal Frequency Division Multiplexing). This modulation allows optimal use of the frequency band, while providing very good resistance to interference. However, one of the problems with these modulations is the cardinal sinus frequency response of the transmitter and receiver filters. Thus, the idea of using filters other than rectangular filters can be considered to overcome this problem. In this direction, oversampled OFDM modulation has been proposed in this work. The main objective of this paper is to analyze the performance of the oversampled OFDM modulation in terms of the PSD (Power Spectral Density) and the BER (bit error rate). From simulation, we can conclude that the performance of the oversampled OFDM technique surpasses the conventional OFDM in terms of BER and PSD

The 3 dB, 90° coupler is a passive device with four ports that allows each output to collect half the input power but in phase quadrature. The 3 dB coupler is often made in microstrip technology where different quarter-wave sections are present to ensure impedance matching. In order to be able to design a duplexer operating on several frequency bands, a tunable hybrid coupler was designed in this work. The coupler must be adjustable to operate on the bands 3.3-3.6 GHz and 4.8-5 GHz. The proposed coupler will cover the bandwidth requirements of 5 bands (3.3-3.6 GHz) and (4.8-5 GHz) to be deployed in China. The hybrid coupler will be designed by two methods. At the first stage, the coupler will be designed by lumped elements, and then it will be designed using transmission lines. Via the ADS tool, the 3 dB 90° coupler is dimensioned and simulated to work well at the center frequency of 3.45 and 4.9 GHz. These two frequencies are belonging to the 5G bands. The main purpose of this work is to simulate and analyze the proposed coupler for 5G frequency bands. The simulation of the reflection coefficient, i.e., S11 parameters in amplitude and phase are presented and discussed. From simulation results we observed that the proposed coupler works under the requirement of 5G application.

A low cost dual band offset fed monopole microstrip antenna is proposed in this paper. The suggested antenna is designed using an inexpensive 1.6 mm thick fr-4 substrate of relative permittivity 4.4. The design and analysis of the proposed antenna model have been performed using HFSS software. By inserting a square slot loaded with an inverted metallic structure in the patch and the presence of a partial ground plane, dual band operation with an extremely wide bandwidth for the higher band can be obtained. A comprehensive analysis of characteristics parameters (S11, gain, radiation patterns) including distribution of surface current of the suggested antenna is furnished in this paper. The prototype of the fabricated antenna has an attractive compact dimension of only 22 x 19 x 1.6 mm3. The reported measured bandwidths are 800M Hz (4.2-5.0 GHz) and 4200 MHz (8.0-12.2 GHz) for the lower and upper bands, respectively. The measured peak gains across the two operating bands are 3.0 and 4.3 dBi, respectively. The measured results are well accepted and verify the simulated results and hence validates the appropriateness of the design concept. The proposed antenna covers the bandwidth requirements for INSAT (4.4-4.8 GHz) and microwave X-band (8-12 GHz) systems. The compact size, low cost, simple monopole configuration, dual band resonance characteristics, wide bandwidth, good gain, and stable radiation patterns are the advantages of the designed antenna.

In recent years, we are witnessing an exponential development of new applications and technologies in the fields of health, media, industry, transport, energy. This evolution goes hand in hand with the emergence of new services related to a multiplication of connected objects. Faced with these challenges, a new revolution is coming with a new standard of mobile telecommunications systems, referred to as 5G technology. This work presents an investigation of an equivalent circuit model for a 5G microstrip patch antenna. The purpose of this paper is to model an antenna with electrical circuit. In this direction, the proposed antenna was designed by two methods then compared in term of S11. Firstly, the antenna was designed by HFSS (High Frequency Structure Simulator) software. Then, the same antenna was designed by an equivalent circuit by using the optimization tool in ADS (Advanced design system) software. The results obtained from the two softwares were compared in terms of the reflection coefficient, i.e., S11. It has been demonstrated that the results from ADS are in good agreement with those from HFSS. Other parameters are discussed in this paper such as VSWR (Voltage Standing Wave Ratio), E-plane and H-plane of the proposed antenna and real and imaginary part of input impedance of the proposed antenna. From simulation results, we can conclude that the proposed equivalent circuit is validated by mean of simulations.

The objective of this article is to study the performance of the RFID (Radio Frequency Identification) technology and especially the passive UHF RFID (Ultra High Frequency RFID) tags by mean of simulation. In this paper, three patch antennas with different matching techniques for passive UHF-RFID tags are proposed. T-Match, inductively coupled loop and nested-slots layouts are adopted in order to achieve complex impedance matching between the antennas impedance and the chip selected at 915 MHz with high performance. The antennas are printed on a Rogers RT/duroid 5880 substrate with a relative permittivity of 2.2 and thickness of 1.575 mm. Studies demonstrate that the inductively coupled loop and the nested-slots matching techniques are the good candidates to adapt the antenna impedance to chip impedance, while adaptation in T is intended to be only used for dipole antennas. We have achieved an adaptation of 99.90 %, a very wide bandwidth of 409.6 MHz, a broadside an asymmetrical radiation pattern in the E-plane, a read range of 21.19 m and an antenna gain of 4.17 dB with the inductively coupled loop matching technique, while with the nested-slots matching method, we have acquired an adaptation of 99.94 %, a directive antenna, a read range of 19.83 m and a gain of 3.59 dB.

Power line communication (PLC) system is an attractive technology for Smart Grid applications. One key benefit of PLC is its low installation cost because, in PLC technology, we do not need to install any extra cable to extend a network due to the accessibility to low voltage power network. Orthogonal frequency division multiplexing (OFDM) is widely used in PLC networks. Currently, Multiple Input Multiple Output (MIMO) technology is one of the processing techniques appropriate to PLC networks, allowing high data rate. In this work, the MIMO-OFDM system is established to provide better performance over the PLC system by providing communication links with substantial diversity and capacity. However, adapting MIMO to the PLC network involves solving several issues such as MIMO PLC channel modelling and optimisation of the modulation parameters. In this paper, we present measurements results of the transfer function and impulsive noise in the extended frequency range 2-100 MHz. In the simulation part, we evaluate the performance of the proposed receivers in 2×2 MIMO-PLC channels. It is shown that the minimum mean square error (MMSE) receiver can be one of the appropriate candidates for MIMO PLC channels due to its bite error rate (BER) characteristics under impulsive noise.

Orthogonal frequency division multiplexing (OFDM) is a multicarrier transmission system that can achieve high data rate over wireless channels. At the same time, multiple input multiple output OFDM (MIMO-OFDM) in wireless communication systems has been exposed to offer significant improvement over wireless technology by providing transmit diversity. It has become a promising technique for high-performance 5G broadband wireless communications. However, the main problem associated with MIMO-OFDM is that its signal exhibits high peak-to-average power ratio (PAPR), which causes nonlinear distortion and consequently performance degradation. Besides, PAPR carries weaknesses such as an increase in power consumption of high power amplifier (HPA) and analog to digital converter (ADC). Thus, 5G base stations will push up power requirements because energy consumption grows with the number of transceiver elements. So, mobile operators must find the right compromise that, on the one hand, guarantees a certain level of performance to a data flow, and, on the other hand, the energy cost generated for the deployment of the network. For this, as part of the management of power consumption, we propose MIMO constant envelope OFDM (MIMO-CE-OFDM) technique. In this work, we used MIMO-CE-OFDM to mitigate the nonlinear effect of HPA and ADC. To perform practical simulations, we have used COST 2100 MIMO channel model. In this paper, a MIMO-CE-OFDM system has been presented and analyzed under COST 2100 channel model conditions. Simulation results are given to illustrate the performance of 2×2 MIMO-CE-OFDM in the presence of both HPA and ADC nonlinearity. This work shows that the effect of nonlinearity is shown to be negligible on MIMO-CE-OFDM signal.

Orthogonal Frequency-Division Multiplexing (OFDM) is a multicarrier modulation that has expanded attractiveness and is used for wireless communication system. However one key weakness of OFDM signal is the high Peak-to-Average Power Ratio (PAPR). The high PAPR of OFDM signal cause nonlinear distortions by the power amplifier, which in turn affects negatively the OFDM transmission signal. These nonlinearities in amplifiers cause both Inter-Symbol Interference (ISI) and inter-carrier interference (ICI) in the system. A “power back-off” is required to prevent spectral broadening and performance degradation from inter-modulation distortion. To overcome this problem we propose Constant Envelope OFDM (CE-OFDM) which provides a good solution to the high PAPR issue in OFDM. OFDM signal is transformed, by way of Phase Modulation (PM), to a constant envelope signal, thereby alleviating the need for a power back-off and allowing for the most efficient power amplifier operation possible. In this paper the implementation of Maximum-Likelihood Sequence Estimation (MLSE) channel equalization in CE-OFDM-PM is proposed, a performance gain comparison and evaluation over fast fading channels well be presented and discussed. At the same time, Multiple-Input Multiple-Output (MIMO) system is found to provide better performance over wireless channels by providing communication links with substantial diversity and capacity. Likewise for MIMO system, simulation results are given in terms of BER (Bit Error Rate) to show the performance gain of the Alamouti code and of the proposed receiver. The simulation results show that the Minimum Mean Square Error (MMSE) is the best one to avoid ISI.

5G has been planned to meet the strong data advancement and accessibility of the present society. In the proposed work, a new rectangular antenna that has high bandwidth millimeter-wave, stable radiation patterns, and improved reflection coefficient at 28 GHz for future 5G applications, has been designed and fabricated. The FR-4 substrate having a very compact dimension (5.5× 4.35) mm2 with a dielectric constant of 4.4, the thickness of 1.6 mm and loss tangent of 0.002 is used for the design and fabrication of the proposed antenna. The proposed configuration has been designed and simulated by using HFSS (High-Frequency Structure Simulator) simulator which is based on the finite element method. The impedance bandwidth achieved by the designed antenna is about 4.10 GHz (25.8 GHz-29.9 GHz) and has a reflection coefficient of about -39.70 dB, with a maximum gain of 5.32 dBi. The measurement results are in good agreement with the simulated results.

The need for high bandwidth in wireless systems has been increased because there is always unoccupied bandwidth for the current communication system. Therefore, the extension of communication systems to higher frequencies is required to offer high-capacity wireless applications. In order to achieve high capacity, the carrier frequencies requisite should be increased more than 100 GHz. Nowadays, academics are currently working on wireless communication systems at terahertz (THz) frequency which is attractive for wireless communications since they lead to high capacity. However, the THz channel is a harsh environment for signal transmission. So, the implementation of THz communication system requires the study of modulation schemes. Among various kinds of communication techniques, QPSK and BPSK are suitable due to their simplicity. In this work, quadrature phase shift keying (QPSK) and binary phase shift keying (BPSK) are assumed with incoherent and coherent receiver, respectively. When it comes to opting for the appropriate modulation techniques for THz communication system, there is always a compromise to be made between bandwidth efficiency and power efficiency. For that reason, the performance modulation schemes were analyzed in terms of data rate and power efficiency. Besides, multiple-input multiple-output (MIMO) can provide high capacity by using multiple transmit or receive antennas. This chapter evaluates the performance of QPSK/BPSK modulations for single-input single-output (SISO) and MIMO technics under different values of the roll-off factor considered for root raised cosine (RCC) filter; then we analyze the performance of MRC receiver in MIMO wireless channels with Alamouti encoding at THz frequencies.

The fifth generation (5G) wireless network technology is to be standardized by 2020, where main goals are to improve capacity, reliability, and energy efficiency. Constant envelope orthogonal frequency division multiplexing (CE-OFDM) is a technique to modify the OFDM signal with high peak-to-average power ratio (PAPR) to a constant envelope zero decibel PAPR waveform, in order to minimize energy consumption in future wireless communication systems (5G). The conventional CE-OFDM uses inverse discrete Fourier transform (IDFT) to calculate the signal time samples before feeding them to the phase modulator. In this paper, the performances of the CE-OFDM are studied in terms of the BER over AWGN channel and frequency-selective fading channel.

Power line communications (PLC) network is one of the promising communication technologies for data transmission and information exchange in indoor distribution networks, because it does not require any new wiring installations, which can significantly reduce the deployment costs. This network is a practical solution for connecting all computer and multimedia devices to each other and to the telecommunication network, but there are still several problematic areas in data transmission over power lines cables. The power line channel is harsh environments for signal transmission. Indeed, many factors influence the communication path and path losses. These factors include the cable type, loading conditions, impedances, the types of devices or appliances connected to them. In this work, we focus on investigating these factors via simulations results of the transfer function of the indoor PLC channel. In addition we study the effect of line, branched line length, the number of branched, and impedance of devices connected to the PLC network on the performance of PLC Technology.

5G advancements will revolutionize the manner in which most high bandwidth speed clients get to their wireless application. In this paper, a broadband square slotted 2 x 1 slotted patch antenna array has been proposed for 5G cellular applications operating at 30 GHz. The slotted antenna array has been designed and simulated on FR4 substrate with relative permittivity ϵr of 4, 3. Having dimensions 4.6 x 5.2 x 0.3m m3 for slotted single patch antenna and 9.2 x 13.2 x 0.3m m3 for 2 x 1 slotted patch antenna array. The proposed antenna consists of square slotted radiating single patch feed by a 50 Ohm microstrip line and power divider are used to feed the tow elements. Our goal is to obtain a high bandwidth with reduced losses and to get a higher Gain, to be especially used for 5G. The point of this paper is to plan and simulate a square slotted patch antenna array using ANSO FT-HFSS and CST.

In this letter, a looped slots patch antenna for passive UHF-RFID tags applications in metallic supports is presented. By adopting a three-layer substrate on antenna design, an antenna gain of 2.5 dB on metallic objects is achieved; and by embedding a looped slots on the radiating body, an overall size of the antenna of 85 x 85 x 3.862 mm3, is obtained, and a good matching between the antenna impedance and chip is established. The simulated half-power bandwidth of the designed antenna is of 96.8 MHz which allows to cover all passive UHF-RFID band. The read ranges in free space and on metallic supports are 12.5 and 16 m, respectively, which implies that the proposed antenna is a good candidate to work on metallic objects of large dimensions such as the containers.

The objects with high conductivity such as metals consist of a challenge for passive RFID (Radio Frequency IDentification) tags in UHF (Ultra High Frequency) due to their effects on tags antennas performance. In this paper, a passive antenna for UHF RFID tags applications on metallic supports is presented. The antenna structure is constituted of a rectangular patch with looped slots printed on three-layer substrate and deposited on a regular ground plane. The looped slots are used to match the antenna impedance to the chip impedance in order to maximize power transfer. The three-layer substrate is adopted to improve the antenna gain, and the regular ground plane is added to act as fixed-size metallic plate. The antenna performance in free space and the one attached to the metallic surfaces are compared. The metallic plate size variation effects on antenna performance are studied by fixing the proposed antenna over different sizes of square copper plates which are multiple to the antenna size, and evaluated using the 3D electromagnetic simulator: HFSS (High Frequency Structure Simulator). The proposed antenna is designed to be used on high dimensions metallic objects such as the containers. It achieves a stable performance when the metallic surface size is five times larger than the antenna size: A read range of 16 m, an antenna gain about 2.5 dB and a bandwidth that covers all passive UHF-RFID band. Copyright © 2019 Praise Worthy Prize S.r.l. - All rights reserved.

This paper presents the implementation and evaluation of rectifier prototype and diode modelling. Our design is based on the optimization of a compact rectifier circuit with single Schottky diode HSMS-2820 for MPT (Microwave Power Transmission) Applications at frequency 2.45GHz. This rectifying method is used to transform an alternating signal into a mono-alternating signal (unidirectional) at 2.45 GHz. These Schottky diodes are specifically designed for both analog and digital applications. in such applications, we work with a very low input power around -20 dBm. To overcome this problem, Rectifier with Impedance Matching Circuit will be used, with a low-pass filter with radial sections or with a compact structure. In this work we analyze the rectifier circuit behavior by using ADS Agilent software.

One key weakness of multicarrier signals such as OFDM (Orthogonal frequency division multiplexing) is the high peak-to-average power ratio (PAPR). Nonlinear distortions caused by the power amplifier are aggravated by high PAPR, which in turn affects the OFDM signal. These nonlinearities in amplifiers cause both inter-Symbol interference (ISI) and inter-carrier interference (ICI) in the system. A “power back-off” is required to prevent spectral broadening and performance degradation from inter-modulation distortion. Constant Envelope OFDM (CE-OFDM) provides a solution to the high PAPR issue in OFDM. OFDM signal is transformed, by way of phase modulation (PM), to a constant envelope signal, thereby alleviating the need for a power back-off (IBO) and allowing for the most efficient power amplifier operation possible. In this paper the implementation of MLSE (Maximum-Likelihood Sequence Estimation) channel equalization in CE-OFDM-CPM is proposed, a performance gain comparison and evaluation over fast fading channels well be presented and discussed.

This paper presents the improvement of radiation characteristics performances of the RFID array antenna for detection system of objects or living things in motion. The proposed array antenna is composed of two identical elements, connected in parallel via simple microstrip line divider, having a power port adapted to 50 Ω. This array is designed using RT/duroid-5880 substrate with the following parameters: loss tangent tan δ = 9.10−4, εr of 2.2 and substrate’s height of 1.56 mm. The total size of this array antenna is (110.5 × 83)mm2.The simulation results obtained in this work show that the proposed array antenna has a high gain about of 9.22 dB, a good reflection coefficient S11 of - 25.36 dB, and a good adaptation at the 2.4 GHz microwave band.

5G denotes the next major phase of mobile telecommunications standards beyond the current 4G, which will operate at millimeter-wave frequency band. In any wireless device, the design of an efficient antenna has a positive impact on overall system performance. This paper presents a high gain millimeter-wave microstrip antenna array with a simple profile structure-Operating at 29.8 GHz. Based on the best optimized single element patch, a 4 element patch array antenna is proposed. The antenna's is designed on a compact Roger RO3006 substrate with relative permittivity (ϵ r) of 6.15 having dimensions 7×14.5 × 0.13 mm3 for 2×1 and 9 × 27 × 0.13 mm3 for 4×1 at the resonant frequency of the antenna is 29.8 GHz. Return loss, VSWR and radiation patterns were simulated by ANSOFT HFSS. The simulation result of VSWR was compared to this obtained by CST MWS.

RFID (Radio Frequency IDentification) in UHF (Ultra High Frequency) has received considerable attention due to the different advantages offered in various fields. The tags in this technology must be attached to small objects. Therefore, the antennas size needs to be miniaturized without significant degradation. In this paper, a novel miniaturized tag antenna for UHF RFID applications is presented. The miniaturized antenna is composed of a folded line and an inductively coupled feeding loop: the antenna line is folded to reduce the antenna size, and the inductively coupled loop is used to match the antenna impedance to the chip to maximize power transfer. The miniaturized antenna is designed to operate in the USA band at around 915 MHz, and printed on a polyester substrate with a thickness of 50 µm. The performances of the proposed antenna regarding impedance, reading distance, return loss and antenna gain are evaluated using a 3D electromagnetic simulators HFSS (High Frequency Structure Simulator) and CST-MWS (Computer Simulation Technology-MicroWaves Studio) and are compared to those achieved by the conventional dipole antenna with an inductively coupled loop.

The impedance matching between an RFID IC (Radio Frequency IDentification-Integrated Circuit) and an RFID tag antenna is of a critical importance in RFID tag design. A poor match impedance results in less power delivered to the RFID IC and poor antenna performance that lead to poor communication between the reader and the tag. In this work, we search to match the input impedance of the planar dipole antenna for the UHF RFID (Ultra High Frequency) applications to a RFID chip at 915 MHz. To achieve this goal we have adopted the most popular method of adaptation 'T-Match' which enables proper matching between the tag and the chip for maximum power transfer. HFSS (High Frequency Structure Simulator) tool was used as a platform to design, to match, to optimize and to present the circuit and the radiation parameters of the antenna printed on a flexible substrate. The results obtained by HFSS were compared to those obtained by CST MWS (Computer Simulation Technology-MicroWaves Studio). The match between the chip and the antenna is computed in terms of the power transmission coefficient.

Power Line Communications have been the subject of an important research work. At the same time, the growing demand for multimedia communications provides a good prospect for PLC as a promising transmission technique for the "last mile" access network. Orthogonal Frequency Division Multiplexing (OFDM) is a spectrally efficient multicarrier modulation technique for high speed data transmission over multipath fading channels. High Peak-to-Average Power Ratio (PAPR) is a major drawback of OFDM. The high PAR of the OFDM signal has to be considered when setting the range of the digital-to-analog converter (DAC) and dimensioning the line-driver. This paper introduced an improved PAPR reduction scheme using constant envelope modulation. Furthermore, by utilizing continuous phase modulation (CPM) in a CE-OFDM system, the PAPR can be effectively reduced to 0 dB. The paper describes a CE-OFDM based modem for Power Line Communications (PLC) over the low voltage distribution network. Relying on a preliminary characterization of a PLC network, a complete description of the modem is given. © 2013 Praise Worthy Prize S.r.l. - All rights reserved.

Power Line Communications have been the subject of an important research work. At the same time, the growing demand for multimedia communications provides a good prospect for PLC as a promising transmission technique for the "last mile" access network. Orthogonal Frequency Division Multiplexing (OFDM) is a spectrally efficient multicarrier modulation technique for high speed data transmission over multipath fading channels. High Peak-to-Average Power Ratio (PAPR) is a major drawback of OFDM. The high PAR of the OFDM signal has to be considered when setting the range of the digital-to-analog converter (DAC) and dimensioning the line-driver. This paper introduced an improved PAPR reduction scheme using constant envelope modulation. Furthermore, by utilizing continuous phase modulation (CPM) in a CE-OFDM system, the PAPR can be effectively reduced to 0 dB. The paper describes a CE-OFDM based modem for Power Line Communications (PLC) over the low voltage distribution network. Relying on a preliminary characterization of a PLC network, a complete description of the modem is given. The good performances of the BER have been checked by the simulation platform of PLC channel using Matlab.