Wireless Applications Research Articles

Design of a Compact Wideband Two-Port MIMO Antenna for NR 5G Sub-6 GHz Band Wireless Applications

Design of a Compact Wideband Two-Port MIMO Antenna for NR 5G Sub-6 GHz Band Wireless Applications

Computationally optimized multi‐port antenna systems for WLAN/Wi‐Fi (IEEE 802.11a/h/j/n/ac/ax), 5G (mid‐band), and UWB applications

SummaryThis paper presents computationally optimized 2‐element and 4‐element Multiple‐Input, Multiple‐Output (MIMO) antennas for WLAN/Wi‐Fi, 5G, and UWB applications. The antenna configuration is constructed with the orthogonal placement of sawtooth‐shaped circular monopole radiating elements. The Particle Swarm Optimization (PSO) and Covariance Matrix Adaptation Evolution Strategy (CMA‐ES) optimization techniques are employed to achieve the best performance and size of the proposed antenna. Among these optimization techniques, CMA‐ES is identified as the better approach. The final optimized geometry of the 2‐element and 4‐element MIMO antennas is 49.40 mm × 24.22 mm and 49.44 mm × 45 mm, respectively. Both optimized antennas are fabricated and experimentally verified. The fractional bandwidth of the antenna is more than 110.3%, and more than −20 dB isolation is attained without employing any decoupling method. The Envelop Correlation Coefficient (ECC), Directivity Gain (DG), Total Active Reflection Coefficient (TARC), and Channel Capacity Limit (CCL) are 0.0001, 9.99, < −15 dB, and 0.1 bits/s/Hz, respectively. The proposed antenna is a good candidate for numerous current wireless applications due to its size and performance.

Aggregation Induced Emission-Based Covalent Organic Frameworks for High-Performance Optical Wireless Communication.

Here, we report the first utilization of covalent organic frameworks (COFs) in optical wireless communication (OWC) applications. In the solid form, aggregation-induced emission (AIE) luminogen often shows promising emissive characteristics that augment radiative decays and improve fluorescence. We have synthesized an AIE-COF through the Knoevenagel condensation reaction by taking advantage of the ability to carefully design and alter the COF structure by integrating an AIE luminogen with linear building blocks. The synthesized AIE-COF exhibited a high solid-state photoluminescence quantum yield (∼39%) and a short photoluminescence lifetime (∼1 ns), crucial for achieving modulation bandwidth for high-speed OWC applications. For comparison, we constructed an aggregation-caused quenching based COF, showing a similar lifetime but almost insignificant quantum yield. The orthogonal frequency-division multiplexing modulation strategy employed by the AIE-COF demonstrates remarkable high-rate data transmission, with a wide -3 dB modulation bandwidth of nearly 200 MHz and achieving high net data rates of 825 Mb/s, outperforming traditional materials. These results open new avenues for the ability to design and finetune new COF materials for their utilization as color converters in developing cutting-edge OWC components, enabling faster and more efficient data transfer.

Wireless sensor networks protocols, applications, and network-on-chip communications

A wireless sensor network (WSN) is a network consisting of self-governing sensors that are deployed in space and communicate with each other using wireless technology to monitor physical or environmental variables. These networks generally include compact, inexpensive sensor nodes equipped with sensing, processing, and communication functionalities. WSNs are specifically engineered to gather data from their immediate environment, do local data processing, and subsequently communicate pertinent information either to a central hub or to other interconnected nodes within the network. Continuous research in the domain of WSNs is devoted to advancing security concerns, developing novel sensing technologies, and optimizing communication protocols. The advancements in these domains enhance the ongoing development and efficiency of WSNs. The WSNs are very important for getting information from the real world in many situations. WSNs are flexible tools for keeping an eye on and controlling different environments because they have sensor nodes, wireless communication, and distributed processing. WSNs use network-on-chip (NoC) communication architecture to connect sensor nodes. The article explains the introduction to WSN, the background of wireless communication, motivation, ZigBee protocol, and WSN applications.

A Systematic Review of Meta‐Surface Based Antennas for Thz Applications

AbstractThe growing demand for advanced wireless communication, high‐resolution imaging, and innovative medical applications in the Terahertz (THz) frequency range has driven remarkable developments in meta‐surface‐based antennas. This comprehensive review delves into the cutting‐edge advancements, novel designs, and practical applications of meta‐surfaces in the THz spectrum. The review begins by exploring the materials employed in meta‐surfaces and their crucial role in achieving efficient THz operation. It delves into the realm of polarization diversity, revealing innovative approaches to harnessing the potential of meta‐surfaces for polarization control and conversion. A key area of focus is beam‐steering technology, with a thorough investigation into beam‐steering techniques that have significant implications for enhancing wireless communication, high‐resolution imaging, and the internet of things. The paper highlights the potential of these techniques in addressing real‐world challenges and advancing THz technology. Furthermore, this review provides an in‐depth examination of the innovative antenna designs tailored for THz applications, shedding light on their characteristics and benefits. It also explores the exciting possibilities of THz technology within the medical field, including precise bio sensing and cancer cell detection.

Design and performance analysis of compact quad‐band two‐port sickle‐shaped MIMO antenna for wireless applications

AbstractIn this research, a quad‐band sickle‐shaped MIMO antenna of compact size 32 × 32 mm2 (0.28λ0 × 0.28λ0 at lower resonant frequency 2.6 GHz) has been proposed using partial ground and tilted isolation stub at an angle of 45°. It covers 2.40 to 2.80 GHz frequency range with bandwidth (BW) of 15.38% (0.40 GHz) which is applicable for Wi‐Fi application in first band and in second band it covers from 4.48 to 5.75 GHz frequency range with BW of 24.83% (1.27 GHz) for WLAN application. In addition, the third band starts from 9.75 to 10.43 GHz frequency range with BW of 6.74% (0.68 GHz) for the X‐band whereas in fourth band it covers from 13.07 to 15.87 GHz frequency range with BW of 19.38% (2.8 GHz) frequency, which is applicable on Ku‐band application. Moreover, the isolation is < −15 dB in the entire resonating frequency band which is an acceptable limit for reduction of mutual coupling. ECC value is <0.5 in the entire operating band of frequency. The diversity gain of the proposed MIMO antenna is approximately 9.96 dB that shows the antenna exhibits good diversity property. The channel capacity loss value is <0.4 bps/s/Hz in the entire resonating band. In view of all the diversity parameters, the proposed MIMO structure fulfills all the requirements of the MIMO antenna.

IoT Wearable Machine Devices Based on Optical Sensors and Wireless Networks Application in Community Fitness Data Analysis

IoT Wearable Machine Devices Based on Optical Sensors and Wireless Networks Application in Community Fitness Data Analysis

Planar Rectangular Microstrip Patch Antenna Array with Corporate-Feed Network for Gain Enhancement

Abstract: The design and performance analysis of a inset-fed planar rectangular microstrip patch antenna array with corporatefeed network systems is presented in this paper. This design aims to increase the gain of the rectangular patch antenna through the use of a 16-element planar rectangular antenna array. Each element in this planar array is fed by T-junction power divider networks with quarter-wave transformer lines via the corporate-feed method. The antenna is designed over the operating frequency of 2.4 GHz using the substrate material FR-4, which has a dielectric constant of 4.4 and a loss tangent of 0.002. By the addition of radiating patches in the array design, the gain, directivity and bandwidth also has been improved significantly. The proposed antenna array provides a gain of 9.284 dB, a directivity of 16.2 dBi, and a bandwidth of 0.361 GHz. The designed antenna can be used for wireless applications.

A dual-band meandered line antenna loaded with metasurface for wireless applications

In this paper, a metamaterial inspired meandered line loaded antenna with dual-band characteristics for wireless applications is presented. Initially, the antenna is loaded with a single meandered line structure and operates over a single band with a center frequency of 5.64 GHz and circularly polarized (CP) radiation. Further, it is loaded with two more similar meandered line structures inducing an extra band with a center frequency of 3.4 GHz and hence operating as a dual band antenna with an impedance bandwidth of 11.4% and 33.7%, respectively, exhibiting CP radiation in its second band. Moreover, the antenna is backed with a metasurface (MS) at the ground side with a separation of 18.4 mm to enhance the gain and radiation of the antenna. The antenna exhibits good radiation characteristics with peak gains of 7.66 dBi and 8.7 dBi in the first and second bands, respectively. The antenna is fabricated, and promising experimental results have been observed.

Quad-band dual-port MIMO microstrip antenna with double integrated circularly polarized bands for 4G/5G wireless applications

Abstract A quad-band two-port MIMO antenna is presented with four operating bands at 2.4, 3.5, 5.8, and 8.2 GHz to serve WLAN, 4G LTE, 5G & ITU applications, respectively. The wide impedance bandwidth of 13.33% (2.28–2.60 GHz), 21.62% (2.98–3.74 GHz), 8.9% (5.58–6.10 GHz) and 4.8% (8.00–8.44 GHz) is achieved at respective operating bands. The antenna also provides circular polarization at 3.5 GHz and 5.8 GHz. It is fabricated on FR4 substrate of 50 × 76 × 1.6 mm3 dimensions. The isolation between both ports is below 28 dB within all four operating bands. The radiation efficiency is about 90% in the first two bands whereas it is about 75% in the remaining two bands. The presented MIMO antenna shows better radiation characteristics along with satisfactory diversity performance. Experimental results of the fabricated prototype validate the simulated results.

Recent Progress of Iron-Based Magnetic Absorbers and Its Applications in Elastomers: A Review.

As a result of continuing scientific and technological progress, electromagnetic waves have become increasingly pervasive across a variety of domains, particularly within the microwave frequency range. These waves have found extensive applications in wireless communications, high-frequency electronic circuits, and several related fields. As a result, absorptive materials have become indispensable for dual-use applications across both the military and civilian domains because of their exceptional electromagnetic wave absorption properties. This paper, beginning with the operating mechanisms of absorptive materials, aims to provide an overview of the strategies that have been used to enhance the absorption performance of iron-based magnetic absorbers (IBMAs) and discuss the current research status of absorptive material components. The fabrication of a ferromagnetic absorber in terms of morphology, heterointerface coupling, and macrostructural enhancements and the effect of powder characteristics on their electromagnetic properties are discussed. Additionally, the application of IBMAs in elastomers is summarized. Finally, this paper summarizes the limitations of existing ferromagnetic absorber materials and offers a perspective on their potential future developments. The objective of the ongoing research is to fabricate absorptive components that have thin profiles, lightweight construction, wide absorption frequency ranges, and strong absorption capabilities.

Fully tunable microwave photonic narrow bandpass filter using an on-chip dual-drive microring resonator

We propose and experimentally demonstrate a fully tunable microwave photonic narrow bandpass filter based on phase modulation to intensity modulation (PM-IM) conversion. In the filter implementation, an on-chip dual-drive microring resonator (MRR) is a key component. This resonator leverages a multimode waveguide to enable a high Q-factor. A metallic micro-heater and a lateral PN junction are simultaneously created for resonance wavelength tuning. When one driving signal is applied to the micro-heater, a large tuning range of the resonance wavelength is resulted; when another driving signal is applied to the PN junction, a fast tuning speed of the resonance wavelength is caused. By jointly using two different tuning mechanisms, the realized microwave photonic filter features a large frequency tuning range as well as a fast tuning speed. In addition, the filter bandwidth can also be tuned. A silicon-based dual-drive high-Q racetrack MRR chip is designed, fabricated, and evaluated. By incorporating the chip in a microwave photonic filter system, a bandpass filter with a narrow bandwidth of 1.27 GHz is achieved. An ultra-wide frequency tuning range from 3 to 51 GHz, an ultra-fast tuning speed less than 0.54 ns, and a tunable bandwidth from 1.27 to 4.47 GHz is experimentally demonstrated. This fully tunable filter offers significant potential in future radar and next-generation wireless communication applications.

Bidirectional beam generation by metasurface for 6G communication

This paper presents a bidirectional metasurface that is polarization dependent and consists of 2-bit coding reflect-transmit (RT) elements. The proposed metasurface can transmit the vertical polarized (VP) incident wave and reflect the horizontal polarized (HP) wave with the same focal length. The 2-bit coding passive RT elements, named UC0 to UC3, have 0°, 90°, 180°, and 270° phase responses for both vertical and horizontal incidences. The array samples were fabricated using standard print circuit board (PCB) technology. The results of both numerical and experimental investigations demonstrate that the proposed metasurface is capable of beam control with an angular range of ±30° in the xoy, xoz, and diagonal planes. The reflected and transmitted beams have been found to exhibit peak gains of 22 dBi at 94.5 GHz with 7% 3-dB gain bandwidth and 22.1 dBi at 93 GHz with 14.8% 3-dB gain bandwidth, respectively. The proposed metasurface shows great potential for use in 6G wireless communication applications.

Thermal analysis of GaN HEMTs using nongray multi-speed phonon lattice Boltzmann method under Joule heating effect

Gallium Nitride (GaN) high electron mobility transistors (HEMTs) exhibit superior electrical properties for power and radio frequency applications, but performance is compromised by localized Joule heating, increasing channel temperatures. Precise thermal analysis during design is essential for optimizing device architecture and management strategies. Traditional methods like the Fourier heat diffusion equation (HDE) and the phonon lattice Boltzmann method (PLBM) with the D2Q8 scheme inadequately model phonon ballistic transport at high Knudsen numbers. This study introduces a nongray multi-speed PLBM integrated with the drift-diffusion model to analyze electro-thermal processes in GaN HEMTs. Validated through simulations of thermal conductivities in two-dimensional GaN thin films, the approach examines internal temperature rise in GaN HEMTs under different gate voltages, comparing results with HDE and gray BTE models, and emphasizing the need for non-Fourier effects in thermal analysis. It also evaluates the impact of GaN layer thickness on temperature distribution, providing a robust solution for thermal analysis in GaN HEMTs and other field-effect transistors.

Longitudinal Tracking of Calprotectin and Interleukin-6 in Sweat and Saliva Using a Sweat Wearable Device

Introduction: This work demonstrates an electrochemical sensor for the application of continuous, noninvasive measurement of inflammation in sweat and saliva through the biomarkers Calprotectin and Interleukin-6 (IL-6), respectively. Calprotectin and IL-6 play a part in the systemic inflammation inherent to chronic inflammatory conditions, such as Inflammatory Bowel Disease (IBD), rheumatoid arthritis, cystic fibrosis, etc. Sweat and saliva represent comparable external mediums through which inflammation can be tracked continuously and noninvasively. Materials and Methods: Calprotectin and IL-6 were measured in sweat and saliva for 2 chronically inflamed subjects and 10 healthy subjects over a two-day period. Sweat measurements were performed using a wearable, skin-based electrochemical sensor utilizing electrochemical impedance spectroscopy (EIS) to quantify Calprotectin and IL-6 concentrations continuously in passively expressed sweat. Calprotectin and IL-6 levels were measured in real time and transmitted to a wireless device application. Figure 1 illustrates the sensor and wearable device design and composition alongside an application interface displaying the wearer's Calprotectin levels measured in real time. Synchronously collected saliva was measured for Calprotectin and IL-6 to characterize the relationship between sweat and saliva expression, establish the relationship between Calprotectin and IL-6 expression as markers of chronic inflammation, and investigate the sweat and salivary diurnal patterns of marker expression for inflamed and healthy subjects. In addition, we tracked sweat Calprotectin over a 40-hour period for chronically inflamed and healthy subjects with varying levels of inflammation and treatments. Results and Discussion: Between sweat and saliva, Calprotectin and IL-6 demonstrated a strong linear relationship (R2>0.7), and strong to moderate linear relationships between Calprotectin and IL-6 in sweat and saliva, respectively. Bland-Altman analysis and Deming regression analysis determined a low incidence of outliers and similar ranges of Calprotectin and IL-6 expression between sweat and saliva. Diurnal analysis exhibited significantly higher sweat Calprotectin and higher median Calprotectin measured in the morning-afternoon than measured in the evening among chronically inflamed and healthy subjects, respectively. Among sweat IL-6 measured in the morning-afternoon and evening, chronically inflamed individuals expressed higher median sweat IL-6 in the morning-afternoon, while healthy individuals expressed higher median IL-6 in the evening. Temporal results of 40-hour tracking of sweat Calprotectin demonstrated higher basal Calprotectin in a medicated over unmedicated inflamed subject, and higher basal Calprotectin of inflamed subjects over a healthy subject. Conclusion: Calprotectin and IL-6 demonstrated strong positive linear relationships between saliva and sweat expression of each marker and strong to moderate linear relationships between the markers in sweat and saliva, along with a low incidence of outliers and a similar range of expression between sweat and saliva. Diurnal patterns were characterized for chronically inflamed and healthy individuals for Calprotectin and IL-6 in sweat, and continuous tracking of inflammation in sweat was demonstrated with the wearable sensor device. Figure 1

Audio misinformation encoding via an on-phone sub-terahertz metasurface

We demonstrate a wireless security application to protect the weakest link in phone-to-phone communication, using a terahertz metasurface. To our knowledge, this is the first example of an eavesdropping countermeasure in which the attacker is actively misled.

A MIMO antenna array featuring dual wideband and high gain for 5G NR n257/n258/n260/n261 bands 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.

Dual-band dual-truncated R-slot loaded monopole patch antenna using a single-layer bandstop FSS reflector for gain enhancement

New reflector structure (RS) based on ultra-wide stopband single-layer frequency selective structure (FSS) for mid-band sub-6 GHz 5G applications is designed. The proposed RS is arranged into array of 7 × 7-unit cell of FSS elements for antenna gain and front-to-back ratio enhancement. The single antenna element of volume 30 × 20 × 1.6 (in mm3) consists of a dual-quarter-circular truncated edge-fed rectangular slot (R-slot) loaded rectangular patch (R-patch) antenna with degraded ground structure (DGS) to operate at 3.6 GHz mid-band sub-6 GHz 5G and 5.8 GHz WBAN band. The proposed unit cell FSS element, the RS of volume 55.5 × 55.5 × 13.2 (in mm3) and the associated antenna are designed on lossy thin FR-4 substrate material and investigated numerically using commercial computer simulation technology microwave studio (CST-MS) software. The studied dual-structure based RS made with array of single-layer FSS and monopole R-patch antenna is fabricated and measured. The measured impedance bandwidth (IBW) of 48.28% (3.06–4.85 GHz) and 86.20% (5–10 GHz), peak gain of 5.36 and 7.45 dBi, radiation efficiency of 67.11% and 80.16%, and front-to-back ratio of 12.23 dB and 22.84 dB are achieved at the resonant frequencies 3.5 and 5.8 GHz respectively. The FSS reflector associated with the dual-band monopole R-patch antenna performances are in good agreement with the portable wireless applications requirements.

A review on microstrip patch antenna for wireless communication systems at 3.5 GHz

This article presents a review of several microstrip patch antennas for 3.5 GHz wireless applications. Different substrate materials, FR-4 (loss), FR-4 Epoxy, Rogers RT/droid 5880, TLC-30, and Rogers RT/droid 5880 LZ, are used. In recent years, wireless antenna applications have increased, including biomedical appliances, internet of things (IoT) terminals, edge devices, radars, mobile phones, and many more. In this work, several articles were reviewed and investigated, and several microstrip patch antennas with a resonance frequency of 3.5 GHz were designed using different substrate materials and shapes. This article also discussed the geometric shapes of antennas, antenna properties, sizes of substrate materials, loss tangent, thickness, return loss, bandwidth, voltage standing wave ratio (VSWR), gain, efficiency, and directivity. Several software is used for design and simulation, including computer simulation technology (CST), high-frequency simulation frequency (HFSS), and advanced design system (ADS), FEKO, and MATLAB. The main goal of this paper is to talk about different wireless application papers that work in the S-band at a frequency of 3.5 GHz and have been published in various international journals and conferences.

Suppression of vortex electromagnetic wave divergence by modulating the wave front dislocation line

Abstract When the beam is transmitted in the atmosphere, under the influence of atmospheric turbulence, the beam will occur energy attenuation, wavefront distortion and other phenomena, which will seriously affect the transmission and reception of information. Based on the PB phase principle enhances the focusing capability of the auto-focusing Airy Gaussian vortex beam by regulating the wavefront error curvature of the vortex beam, and then enhances the resistance of the beam against atmospheric turbulence. The results reveal the curvature of the wavefront error curve and the peak intensity of the light field of the beam can be changed by changing the beam polarization state parameters n and m in the focal plane. The auto-focusing Airy Gaussian vortex beam with the polarization state parameters m=1, n=4 increases the peak magnitude of the light field intensity in the focal plane of the auto-focusing Airy Gaussian vortex beam with the polarization state parameters m=0, n=0 to 1.99 times. Demonstrate that geometric phase tuning the auto-focusing Airy Gaussian vortex beams can enhance resistance to atmospheric turbulence. Furthermore, this paper extends this method to the field of millimeter wave. Under the transmission distance of 1km, the peak intensity of the initial vortex electromagnetic wave after the geometric phase adjustment is increased to 3.33 times, and the receiving radius of the target surface is reduced to 0.24 of the initial vortex electromagnetic wave. It shows that geometric phase-regulated vortex electromagnetic wave can suppress vortex electromagnetic wave divergence and have potential applications in wireless communication.