Modern Wireless Research Articles

Miniaturized Coplanar Waveguide-Fed UWB Antenna for Wireless Applications

This study presents a compact ultra-wideband (UWB) antenna fed by a coplanar waveguide (CPW) with huge bandwidth for the demands of modern wireless communities. To overcome some technical limitations of the employed substrate and UWB antenna design, a slotted patch resonator was used to create and simulate this antenna based on Locked-Key topology. It has been printed on a 1.5 mm-thick FR4 substrate with a dielectric constant of 4.4. A feeder with characteristic impedances of 50 Ω has been employed. A CST electromagnetic simulator has been employed to simulate and analyze the antenna design. It is operated within the UWB spectrum with a bandwidth of 10.354 GHz, spanning 3.581 to 14 GHz. The overall surface area is 27 × 25 mm2. The gain and maximum efficiency within UWB are better than 3 dBi and 82%, respectively. The antenna is fabricated, and the simulated results are correlated with the measured ones. Finally, the equivalent circuit models for the antenna and rectifier circuit are simulated and measured.

A quad-port multiple-input-multiple-output system for underlay or interweave cognitive radio

<span lang="EN-US">This paper presents a four-element frequency reconfigurable antenna system that is novel in terms of gathering both underlay and interweave cognitive radio in a single multiple input, multiple output (MIMO) design. Built on a 50×38×0.8 mm3 Rogers RT/Duroid 5880 substrate, this system is constructed of two scanning elements to sense ultra-wide band (UWB) with controllable band notching capabilities and two elements act as communication antennas. Eighteen MIMO modes can be provided depending on the state of the five positive-intrinsic-negative (PIN) diodes in each sensing antenna and the four PIN diodes in each communication antenna. These include a scanning UWB mode, fourteen modes to notch WiMax/Cband/<a name="_Hlk120169348"></a>wireless local area network (WLAN)/Xband/ITU in single/dual/triple/quad band rejection states and three interweave modes where each targeting one of the regions of WiMax/Cband/WLAN. Simulated by CST v.10; results like input reflection coefficient and realized gain verify system's capability to work in each operation mode. Moreover, mutual coupling, envelope correlation coefficient and diversity gain all evidence the performance of the proposed system as a MIMO system. Results, simple and compact profile, wide and flexile range of MIMO operation modes in line with the novelty to handle both underlay and interweave cognitive radio all nominate this system as promising to fulfill the needs of modern wireless communications.</span>

AI in Wireless Design

How is AI being used to address the complexity associated with modern wireless systems. Neil Tyler talks with MathWorks’ Houman Zarrinkoub

Broadband circularly polarized folded transmitarray antenna based on polarization conversion metasurfaces

In this communication, a novel design of compact and low-profile broadband circularly polarized folded transmitarray antenna (CPFTA) is reported. A broadband linear-to-circular polarization conversion metasurface (PCM) with multi-mode operation is initially developed as the sub-reflector, to reflect the y-polarized waves and transmit x-polarized waves into right-handed circularly polarized waves. Additionally, by rotating the circularly polarized transmitters, geometric phase can be exploited for phase compensation. Then, a linear-to-linear PCM with high efficiency is designed as the main reflector. As verification, a CPFTA integrated with a broadband planar feed source and the proposed high-efficiency PCMs at X band is designed, fabricated, and experimentally characterized. The measured results are in good accordance with the simulated ones, revealing a −10 dB impedance bandwidth of 28.7%, a 3 dB gain bandwidth of 22.9%, and a 3 dB axial ratio bandwidth of 31.9%. Meanwhile, the achieved peak gain is 25.2 dBi at 10.35 GHz with a maximum aperture efficiency of 28.3%. Combining the advantages of broadband operation, flat gain, and ease of integration, the proposed CPFTA is an attractive candidate for modern wireless communications.

Analysis of the application of modern mobile wireless network terminal in the tutoring design of college physical education course teaching

Analysis of the application of modern mobile wireless network terminal in the tutoring design of college physical education course teaching

Secure Modern Wireless Communication Network Based on Blockchain Technology

Sixth-generation (6G) wireless networking studies have begun with the global implementation of fifth-generation (5G) wireless systems. It is predicted that multiple heterogeneity applications and facilities may be supported by modern wireless communication networks (MWCNs) with improved effectiveness and protection. Nevertheless, a variety of trust-related problems that are commonly disregarded in network architectures prevent us from achieving this objective. In the current world, MWCN transmits a lot of sensitive information. It is essential to protect MWCN users from harmful attacks and offer them a secure transmission to meet their requirements. A malicious node causes a major attack on reliable data during transmission. Blockchain offers a potential answer for confidentiality and safety as an innovative transformative tool that has emerged in the last few years. Blockchain has been extensively investigated in several domains, including mobile networks and the Internet of Things, as a feasible option for system protection. Therefore, a blockchain-based modal, Transaction Verification Denied conflict with spurious node (TVDCSN) methodology, was presented in this study for wireless communication technologies to detect malicious nodes and prevent attacks. In the suggested mode, malicious nodes will be found and removed from the MWCN and intrusion will be prevented before the sensitive information is transferred to the precise recipient. Detection accuracy, attack prevention, security, network overhead, and computation time are the performance metrics used for evaluation. Various performance measures are used to assess the method’s efficacy, and it is compared with more traditional methods.

A novel pattern agile microstrip antenna for modern wireless communication systems

ABSTRACT This article presents a circular microstrip patch antenna loaded with three complementary split rings (CSRRs) on the ground plane for pattern agility features. The antenna resonated at 5.3 GHz and accommodated the frequency spectrum from 5.1–5.7 GHz for different CSRR combinations. The reconfigurable pattern feature has been produced with three p-i-n diode combinations integrated with the CSRR slot on the ground patch. The CSRR combinations are utilized to change the radiation phase concerning the primary radiating circular patch. The proposed antenna radiation beam can steer from ±15°, 180°, and 0° of the broadside pattern in the elevation plane with a satisfactory gain of 3 dBi. The phase variation for various CSRR combinations concerning the primary antenna is presented. The presented antenna is fabricated on an FR4 substrate and tested in an anechoic environment; the tested results verify the pattern agility of the antenna. The demonstrated antenna is suitable for modern wireless communications like LTE and Cognitive radios. The compact size, simple biasing, and low cost are added advantages of the antenna.

Security for Multi-hop Communication of Two-tier Wireless Networks with Different Trust Degrees

Many effective strategies for enhancing network performance have been put forth for wireless communications’ physical-layer security. Up until now, wireless communications security and privacy have been optimized based on a set assumption on the reliability or network tiers of certain wireless nodes. Eavesdroppers, unreliable relays, and trustworthy cooperative nodes are just a few examples of the various sorts of nodes that are frequently categorized. When working or sharing information for one another, wireless nodes in various networks may not always have perfect trust in one another. Modern wireless networks’ security and privacy may be enhanced in large part by optimizing the network based on trust levels. To determine the path with the shortest total transmission time between the source and the destination while still ensuring that the private messages are not routed through the untrusted network tier, we put forth a novel approach. Toexamine the effects of the transmit SNR, node density, and the percentage of the illegitimate nodes on various network performance components, simulation results are provided.

Genotoxic Risks to Male Reproductive Health from Radiofrequency Radiation.

During modern era, mobile phones, televisions, microwaves, radio, and wireless devices, etc., have become an integral part of our daily lifestyle. All these technologies employ radiofrequency (RF) waves and everyone is exposed to them, since they are widespread in the environment. The increasing risk of male infertility is a growing concern to the human population. Excessive and long-term exposure to non-ionizing radiation may cause genetic health effects on the male reproductive system which could be a primitive factor to induce cancer risk. With respect to the concerned aspect, many possible RFR induced genotoxic studies have been reported; however, reports are very contradictory and showed the possible effect on humans and animals. Thus, the present review is focusing on the genomic impact of the radiofrequency electromagnetic field (RF-EMF) underlying the male infertility issue. In this review, both in vitro and in vivo studies have been incorporated explaining the role of RFR on the male reproductive system. It includes RFR induced-DNA damage, micronuclei formation, chromosomal aberrations, SCE generation, etc. In addition, attention has also been paid to the ROS generation after radiofrequency radiation exposure showing a rise in oxidative stress, base adduct formation, sperm head DNA damage, or cross-linking problems between DNA & protein.

An Interference-Aware Resource-Allocation Scheme for Non-Cooperative Multi-Cell Environment

Inter-cell interference cancellation has been investigated for several decades and has become an elementary technique for modern wireless networks. However, the existing interference cancellation mechanism rarely considers the historical channel variations and interference characteristics. In this paper, we propose an interference-aware prediction-based resource-allocation strategy to deal with multi-cell interference, where the historical noisy channel state and the acknowledgment feedback are fully utilized. Together with the predicted interference patterns, our proposed joint sub-channel allocation and rate selection mechanism can achieve better average throughput performance. Through the numerical as well as the prototyping results, we show that our proposed scheme is able to provide more than 9.7% and 8% average throughput improvement compared with many existing baselines.

A Meta-Model to Predict and Detect Malicious Activities in 6G-Structured Wireless Communication Networks

The rapid leap in wireless communication systems incorporated a plethora of new features and challenges that accompany the era of 6G and beyond being investigated and developed. Recently, machine learning techniques were widely deployed in many fields, especially wireless communications. It was used to improve network traffic performance regarding resource management, frequency spectrum optimization, latency, and security. The studies of modern wireless communications and anticipated features of ultra-densified ubiquitous wireless networks exposed a risky vulnerability and showed a necessity for developing a trustworthy intrusion detection system (IDS) with certain efficiency/standards that have not yet been achieved by current systems. IDSs lack acceptable immunity against repetitive, updatable, and intelligent attacks on wireless communication networks, significantly concerning the modern infrastructure of 6G communications, resulting in low accuracies/detection rates and high false-alarm/false-negative rates. For this objective principle, IDS system complexity was reduced by applying a unique meta-machine learning model for anomaly detection networks was developed in this paper. The five main stages of the proposed meta-model are as follows: the accumulated datasets (NSL KDD, UNSW NB15, CIC IDS17, and SCE CIC IDS18) comprise the initial stage. The second stage is preprocessing and feature selection, where preprocessing involves replacing missing values and eliminating duplicate values, leading to dimensionality minimization. The best-affected subset feature from datasets is selected using feature selection (i.e., Chi-Square). The third step is represented by the meta-model. In the training dataset, many classifiers are utilized (i.e., random forest, AdaBoosting, GradientBoost, XGBoost, CATBoost, and LightGBM). All the classifiers undergo the meta-model classifier (i.e., decision tree as the voting technique classifier) to select the best-predicted result. Finally, the classification and evaluation stage involves the experimental results of testing the meta-model on different datasets using binary-class and multi-class forms for classification. The results proved the proposed work’s high efficiency and outperformance compared to existing IDSs.

Th-Shaped Tunable Multi-Band Antenna for Modern Wireless Applications

A compact, reconfigurable antenna supporting multiple wireless services with a minimum number of switches is found lacking in literature and the same became the focus and outcome of this work. It was achieved by designing a Th-Shaped frequency reconfigurable multi-band microstrip planar antenna, based on use of a single switch within the radiating structure of the antenna. Three frequency bands (i.e., 2007–2501 MHz, 3660–3983 MHz and 9341–1046 MHz) can be operated with the switch in the ON switch state. In the OFF state of the switch, the antenna operates within the 2577–3280 MHz and 9379–1033 MHz Bands. The proposed antenna shows an acceptable input impedance match with Voltage Standing Wave Ratio (VSWR) less than 1.2. The peak radiation efficiency of the antenna is 82%. A reasonable gain is obtained from 1.22 to 3.31 dB within the operating bands is achieved. The proposed antenna supports Universal Mobile Telecommunication System (UMTS)-1920 to 2170 MHz, Worldwide Interoperability and Microwave Access (WiMAX)/Wireless Broadband/(Long Term Evolution) LTE2500–2500 to 2690 MHz, Fifth Generation (5G)-2500/3500 MHz, Wireless Fidelity (Wi-Fi)/ Bluetooth-2400 to 2480 MHz, and Satellite communication applications in X-Band-8000 to 12000 MHz. The overall planar dimension of the proposed antenna is 40 × 20 mm2. The antenna was designed, along with the parametric study, using Electromagnetic (EM) simulation tool. The antenna prototype is fabricated for experimental validation with the simulated results. The proposed antenna is low profile, tunable, lightweight, cheap to fabricate and highly efficient and hence is deemed suitable for use in modern wireless communication electronic devices.

Mutual Coupling Reduction in Dual-Band MIMO Antenna Using Parasitic Dollar-Shaped Structure for Modern Wireless Communication

A dual-band Multiple Input Multiple Output (MIMO) antenna with low mutual coupling is analyzed and studied for Fifth Generation (5G) Sub-6 GHz and Wireless Fidelity (Wi-Fi) 6E frequency-band applications. Each of the identical monopole radiators consists of a rectangular patch, inverted-E, and asymmetrical T-shaped strip to generate 5G Sub-6 GHz and Wi-Fi 6E frequency bands. The deployment of the radiators horizontally with end-to-end separation of 5mm makes the antenna compact with an overall dimension of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$45\times 30$ </tex-math></inline-formula> mm2 ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.37\lambda \times 0.25\lambda $ </tex-math></inline-formula> for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> at the lower resonating frequency of 2.5GHz). The antenna achieves measured impedance bandwidths of 2.39-2.57 GHz and 3.82-6.95 GHz, respectively, at two resonating frequencies of 2.5 GHz and 4.5 GHz. A Parasitic Dollar Shaped Structure (PDSS) introduced between the two monopole radiators to suppress the surface waves of each monopole reduces the measured mutual coupling up to -15 dB throughout the operating band. Furthermore, the measured gain, radiation efficiency, Envelope Correlation Coefficient (ECC), and Diversity Gain (DG) values remain in good agreement with simulated values and are well within the minimum limit set by industry standards. These results affirm the applicability of the MIMO antenna for 5G and Wi-Fi 6E frequency bands.

Overview of Passive Intermodulation in Modern Wireless Networks: Concepts and Cancellation Techniques

Overview of Passive Intermodulation in Modern Wireless Networks: Concepts and Cancellation Techniques

A Wi-Fi Frequency Band Passive Biomedical Doppler Radar Sensor

In the past decades, dramatic investments and growth in wireless communication have occupied more and more radio frequency (RF) spectrum and created a shortage in the available radio spectrum. Hence, spectrum efficiency is a critical issue at the forefront of the research. Compared with conventional radar sensors, which rely on a transmitter and a receiver to detect a target, microwave passive sensing does not require a dedicated transmitter. Therefore, microwave passive sensing can have lower power and lower cost while saving the RF spectrum that is becoming limited in the modern wireless era. Since RF signals exist ubiquitously, microwave passive sensing technology has tremendous opportunities. This article proposes a passive biomedical Doppler radar sensor that operates at the Wi-Fi 2.4-GHz band to detect physiological motions of human subjects with a third-party 2.4-GHz transmitter. The proposed passive radar does not require a reference signal. It has a simple architecture with an LNA and a customized single-input diode-based mixer to maximize the down-conversion gain. Experiment results demonstrated that the proposed passive radar receiver has a voltage gain of 53.9 dB from the antenna output to the mixer output, and it can measure the respiration rate and the heart rate of a human subject successfully. The measured respiration rate and heart rate match the results from a fingertip pulse monitor and a chest band respiration monitor, respectively. Gesture detection was also demonstrated with the proposed passive radar.

High-directive multiband microstrip patch antenna for biomedical applications, inspired by metamaterial

Recent advancements in medical technology impose a limited number of devices for biomedical applications. A variety of techniques are being proposed to improve the performance of novel antenna designs in response to the rapid development of modern wireless technologies. A miniaturised microstrip antenna structure based on metamaterial (MTM) is presented here. The objective of this work is to present a high-directive antenna for wireless systems utilising MTM properties. Directivity is improved by the incorporation of the MTM structure on the ground structure. In order to improve the performance parameters of the antenna for medical applications, this study provides the design and analysis of a multiband patch antenna employing split-ring MTM. The split-ring resonator (SRR) MTM structures are embedded in a unique and novel way in the ground structure of the antenna. So that subwavelength modes get introduced in the patch cavity and a good performance characteristics is obtained. The reference antenna is a rectangular microstrip patch antenna exhibiting a directivity of 1.1823[Formula: see text]dB that resonates at a frequency of 2.32[Formula: see text]GHz. The optimised SRR MTM is positioned in the ground plane of the suggested antenna to increase the directivity of the antenna. This technology covers the frequency range between 2.24 and 3.96[Formula: see text]GHz used for biomedical applications and the ultra-wideband (UWB) range from 4.48 to 9.08[Formula: see text]GHz used for medical applications, industrial and scientific areas. The number of gaps of the rectangular-shaped SRRs is a key component of the enhancement of directivity from 1.1823 to 8.88823[Formula: see text]dB.

Design of rectangular microstrip patch antenna with E-slot

The integration of an E-slot within the conventional microstrip patch antenna structure offers improved radiation characteristics and bandwidth. This research presents the design and analysis of a rectangular microstrip patch antenna with an E-slot. The proposed antenna is designed to operate at a specific frequency in the microwave range. The design process involves determining the dimensions of the rectangular patch, feedline, and E-slot to achieve the desired resonance frequency. The simulation and optimization are carried out using electromagnetic simulation software, considering the dielectric substrate properties and other relevant parameters. The E-slot is strategically placed within the patch structure to enhance the antenna's performance. It acts as an additional resonating element, contributing to increased bandwidth and improved radiation characteristics, such as gain and directivity. The integration of the E-slot modifies the current distribution on the patch, resulting in enhanced radiation properties. The performance of the proposed antenna is evaluated through various parameters, including return loss, radiation pattern, and bandwidth. Overall, the rectangular microstrip patch antenna with an E-slot presents a promising solution for achieving enhanced performance in terms of bandwidth and radiation characteristics. The proposed design opens up possibilities for further advancements in microstrip antenna technology, facilitating the development of an efficient and compact antenna structure for modern wireless applications.

Application of automatic noise bandwidth compensation method of improving spectral characteristics of signal generators

Currently, to collect data on the state of the resources of the agro-industrial complex, groups of unmanned aerial vehicles are widely used, interaction with which is carried out by creating wireless ad-hoc flying networks, communication with which from ground control complexes is provided either using space telecommunication systems of satellites, and by means of one or more nodes of such a network. The continuous tightening of requirements for the technical characteristics and parameters of modern wireless telecommunication systems (especially for increasing the speed of information exchange and communication reliability) force developers to look for new approaches in designing radio transmitting equipment. In particular, it is known that the signal-to-noise ratio is significantly affected by the spectral purity of the signals synthesized using special multi-c hannel radio transmitter signal conditioners. It is shown that in order to improve the spectral characteristics of such shapers, it is possible to use the method of automatic compensation of the noise band of the frequency region in which the most undesirable discrete spectral components are presented Based on the proposed approach, the structural and functional diagram of the carrier waveformer with improved spectral characteristics has been developed, for which the main mathematical relationships (differential equations, transfer functions, noise models) have been obtained, on the basis of which the corresponding simulation has been accomplished, confirming the effectiveness of using the auto-compensation principle.

Behavior Modeling and Digital Predistortion of Mismatched Wireless Transmitters Using Convolutional Neural Networks

In modern wireless compact transmitters, Power Amplifier (PA) behavior is considerably affected by the impedance mismatch between the PA’s output and the antenna’s input. This PA’s output mismatch results in a reflection at the PA–antenna interface. In this brief, reflection-aware PA modeling and digital predistortion (DPD) techniques are proposed to mitigate the negative impact of this mismatch on the forward and reverse models of the PA. An Augmented Convolutional neural network model <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$(\boldsymbol{\Gamma }$ </tex-math></inline-formula> ACNN) is proposed to linearize a Doherty PA under different values of the output mismatch using a single set of coefficients. The developed DPD shows robust performance metrics like normalized mean square error (NMSE), and adjacent channel power ratio (ACPR) under diverse complex output mismatch levels.

Design of a UWB Coplanar Antenna with Step Graded Ground Plane for 5G and Modern Wireless Communication Applications

Design of a UWB Coplanar Antenna with Step Graded Ground Plane for 5G and Modern Wireless Communication Applications