Modern Wireless Applications Research Articles

Standalone-quad-channels diplexer for modern wireless applications based on overlapped MOERRs

Standalone-quad-channels diplexer for modern wireless applications based on overlapped MOERRs

A compact circularly polarized dual port MIMO antenna with DGS and parasitic patch for modern wireless communication and IOT applications

Abstract The article proposes a broadband dual-port planar multiple-input-multiple-output (MIMO) antenna for the lower sub-6 GHz band (1.67 GHz to 3.15 GHz) applications. The simple structure of the MIMO antenna system consists of a semi-annular ring-shaped patch with a covering cap-like structure connected with two symmetrical L-shaped structures. A partial ground with a rectangular mesh-like structure at the center is designed and the same rectangular mesh has been added as the parasitic element with the driven patch to attain circular polarization and enhanced isolation. The miniaturized dimensions of the two-port MIMO antenna system are 0.28 λ 0 × 0.54 λ 0. The suggested two-port MIMO antenna offers a wider impedance bandwidth (IBW) of 61.41% around the versatile resonant frequency of 2.4 GHz. The proposed MIMO also depicts a minimum isolation of 26 dB with an edge-to-edge spacing of 0.19 λ 0. An axial ratio bandwidth of 280 MHz is attained between 2.36 GHz and 2.64 GHz. The proposed antenna shows good IBW with excellent isolation, along with good radiation and MIMO diversity characteristics to operate at 2.4 GHz with circular polarization. The designed MIMO antenna can be utilized for IoT and modern mobile wireless applications as the broad bandwidth covers various IoT communication protocol frequencies such as 1.8 GHz (NB-IoT) and 2.4 GHz (Wireless LAN).

Single/bidirectional pattern and beamwidth reconfigurable array antenna using reconfigurable reflecting surface

AbstractThis study describes an array antenna that allows for reconfiguration of the three significant antenna properties, that is, radiation pattern, half‐power beamwidth (HPBW), and single and bi‐directional beam. A reconfigurable reflecting surface (RRS) has been designed and incorporated with the array antenna on the top and bottom. The RRS works to reflect or pass the incident electromagnetic wave. It enables us to reconfigure from single to multibeam radiation in the ±z direction. It also provides two levels of HPBW, that is, 49.6° and 95°. Eventually, the same three sets of antennae have been stacked and rotated with a 60° angle to achieve the radiation pattern reconfiguration in the entire azimuth plane. It conforms to reconfigure all three antenna properties in six directions at an equal interval of 60° angle. The achieved maximum gain in a narrow beam is 9.56 dBi. The proposed reconfigurable antenna array can be used in modern wireless communication applications.

Design and analysis of frequency selective surface embedded broadband high gain miniaturized antenna

SummaryIncorporating the better impedance matching capability of planar curved radiating patch, a miniaturized broadband planar antenna has been designed, analyzed, and integrated with frequency selective surface (FSS) to accomplish higher gain for various short‐range and long‐range modern wireless communication applications. Physical and electrical volume of the presented antenna is 25 × 20 × 1.6 and 0.25 × 0.20 × 0.016, respectively. The proposed radiating patch is constructed from a conventional rectangular patch by transforming the upper side of the patch into a semi‐circular shape and the lower side of the patch into a staircase‐like shape. Measured outcomes of the designed antenna show a very large operating bandwidth of 19.8 GHz (3–22.8 GHz) with a fractional bandwidth (FBW) of 153.5% and bandwidth dimension ratio (BDR) of 3070. An equivalent circuit model (ECM) of the proposed antenna is developed using an advanced design system (ADS) circuit simulator. The frequency responses of the ECM are compared with the simulation done by CST Microwave Studio Suite software and measurement results, which show good agreement. An FSS structure with stop band from 2–28 GHz is positioned beneath the proposed antenna at optimal position (27 mm below the antenna) to enhance the gain up to 8.9 dBi. The presented antenna and FSS are fabricated on FR4 substrate and experimentally verified using standard microwave measurement setup.

Substrate integrated waveguide cavity‐backed slot antenna with low cross‐polarization over the full bandwidth

AbstractHere, a single‐layered single‐fed slot antenna is realized with low cross‐polarization over the full operating bandwidth. This design consists of a circular‐shaped cavity resonator, employed by using substrate integrated waveguide (SIW) technique and a square‐ring slot on the upper metal cladding of the cavity. The antenna is fed using a probe feed which excites the design in dual mode, that is, slot mode and inset patch mode. Due to the proximity of these dual resonances, the antenna operates over a relatively wider bandwidth than previously suggested designs with the claim of low cross‐polarization. The proposed design helps to realize more than 35 dB of co‐to cross‐pol isolation in both E and H planes. Overall experimental results demonstrate a good radiation performance, it is confirming up to 15–20 dB improvement in cross‐polarization level with enhanced enhancement bandwidth which makes it appropriate for a modern wireless application.

A Miniaturized Reconfigurable Antenna for Modern Wireless Applications with Broadband and Multi-band Capabilities

A Miniaturized Reconfigurable Antenna for Modern Wireless Applications with Broadband and Multi-band Capabilities

Hybrid binary grey wolf naked mole-rat algorithm for fragment-type UWB antenna optimization using time-varying transfer functions

This paper introduces a novel hybrid binary variant of the Grey Wolf Optimizer (GWO) and the Naked Mole-Rat Algorithm (NMRA), called HbGNMR. The primary objective of this hybridization is to overcome the poor exploration and local optima stagnation problems of the basic NMRA as well as the poor exploitation of GWO. HbGNMR incorporates the global search strategy of GWO into the worker phase to enhance exploration, and a mating factor based on simulated annealing-inertia weight is added to the breeder phase to improve exploitation. Moreover, fourteen new time-varying binary transfer functions of two families: seven S-shaped and seven V-shaped functions have been analysed. Among these transfer functions, TVV5 was identified as the most effective in converting solutions from continuous search space to binary search space and maintaining a balance between exploration and exploitation phases. The hybrid performance of HbGNMR is evaluated on twenty-three CEC’05, thirty CEC’17, and eighty CEC’21 benchmark functions. The statistical results demonstrate that HbGNMR outperforms nine well-known state-of-the-art algorithms according to Friedman-test and Wilcoxon rank-sum test. To test the effectiveness of the proposed algorithm for real-world applications, HbGNMR is employed to optimize a large dimensional planar-monopole ultrawideband (UWB) fragment-type antenna structure of an 18 × 18 binary matrix cells. Experimental testing of the prototype is conducted on a vector-network-analyser-based experimental-testbed, which shows good agreement with the simulated results. Furthermore, the optimized structure achieves large bandwidth (3.1-12.6 GHz), excellent gain, and high directivity for the 10 × 15 mm2 compact size UWB antenna geometry. Therefore, the optimized antenna can be utilized for modern wireless applications.

A single layer wideband Vivaldi antenna with a novel feed structure

AbstractAn increase of 7 GHz in the industrial, scientific and medical ISM band around 60 GHz has opened it up for many modern wireless applications such as 5G. This means that new component designs that can cater for this large bandwidth are the need of the hour. The design of a large bandwidth, completely planar and high gain novel Vivaldi antenna is presented. Being a travelling wave antenna and implemented using single metal layer make it an excellent candidate for not only Printed Circuit Board based applications but also the lossy Complementary Metal Oxide Semiconductor technology. For the first time, the feed of the antenna is integrated on the same conductor layer as the antenna itself. Using this design technique the problem of thin gap between the metal layers has been mitigated. The final measured results show that the antenna goes above and beyond ISM band with excellent matching performance from 55 to 84 GHz. A high gain of 7 dBi is maintained over a bandwidth of 57–75 GHz with a radiation efficiency of almost 80%. The results show that the design is quite suitable for integration in a millimetre‐wave transceiver system that can support high data rate applications.

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.

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.

Investigations on Complementary Split Ring Resonator (CSRR) array integrated printed conformal band pass filters for modern wireless communication applications

This paper presents the performance analysis of two different conformal band pass filters (BPFs) loaded with an array of circular complementary split ring resonators (CSRRs). Type-1 bandpass filter has been designed by integrating a 9 × 9 array of circular complementary split ring resonator on the bottom layer of the filter. Similarly, Type-2 bandpass filter has been constructed by loading an array of 5 × 5 split ring resonator on the patch layer of the filter. A comparative study between Type-1 and Type-2 bandpass filters are also evaluated that shows dual pass bands for Type-1 filter and triple pass bands for the Type-2 bandpass filter. Furthermore, the conformality of both bandpass filters are judged through bending deformation analysis with various bending positions at 15°, 30°, 45°, 60° and 90°. During the bending performance analysis, the suggested BPFs retains the dual and triple pass band characteristics without any major deviations in its characteristic's parameters. Various performance parameters like return loss, insertion loss, group delay, bandwidth, and quality factor are measured. Detailed analysis of E and H field distributions and surface current distributions are also presented. The Type-2 bandpass filter shows better performance in terms of filter properties compared to Type-1 band pass filter. Hence, the prototype of Type-2 filter with an area of 30 × 30 mm2 is fabricated and measured. The validated results are agreed with the simulated results which confirms the applicability of the proposed filter for several modern wireless communication applications such as Wi-Max and personal communication systems (PCS) applications.

Analysis of Tripleband Single Layer Proximity Fed 2x2 Microstrip Patch Array Antenna

Microstrip patch antennas that are multiband and downsized are required to suit the high demand of modern wireless applications. To meet this need, a one-of-a-kind triple band array antenna has been proposed. The proposed 2x2 microstrip patch array, which comprises of four hexagon-shaped radiating patches are electromagnetically excited by a centrally positioned microstrip feed line in the same plane along with a slotted ground plane, is investigated. CST Microwave Studio, a powerful 3D electromagnetic analysis programme, was used to design and optimize the array antennas. The 2x2 array antenna was constructed on a FR-4 substrate with a dielectric constant of 4.3, a loss tangent of 0.001, and a height of 1.6mm. To optimize energy coupling from the feed line to the radiating patches, the ground plane has an H-shaped groove cut into it. The suggested 2x2 array antenna's multi- frequency behaviour is shown. Three resonant peaks were detected at 1.891GHz, 2.755GHz, and 3.052GHz. The observed bandwidths for these resonances are 234MHz, 69MHz, and 75MHz, respectively, with measured gains of 7.57dBi, 6.73dBi, and 5.76dBi. The goal of this work is to design, build, and test a single layer proximity fed array antenna. Standard proximity fed array antennas contain two substrate layers; however this array antenna has only one. As a consequence, the impedance matching and alignment are better. Simulated and experimental results showed that the this 2x2 array antenna operates in various important commercial bands, such as L and S bands and the array antenna might be beneficial for a wide range of wireless applications. The proposed antenna has good Impedance, S11, and radiation qualities at resonant frequencies. In this work, the 2x2 array antenna with hexagon-shaped radiating patches was successfully created utilizing the single layer proximity fed antenna concept and gap coupled parasitic patches.

Efficient Scheduling in Space–Air–Ground-Integrated Localization Networks

High accuracy and seamless position information formulates the basis of many modern wireless applications, such as the Internet of Things (IoT) and intelligent transportation systems (ITSs). In this article, aiming at the ground user equipment (UE) those in the “blind spots,” where only limited navigation signals are provided, the temporary aerial-aided “anchors” such as the unmanned aerial vehicles (UAVs) are introduced as alternating solutions. We first give the general fundamental limits of the three-dimensional space–air–ground-integrated localization networks (SAGILNs) using both time and angle measurements. Unlike most existing investigations, we treat aerial nodes as “agents” whose positions are not known beforehand. We then try to formulate an efficient scheduling strategy, where proper network <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">behaviors</i> , including the resource optimization and UAV deployment, are provided. We find that the proposed scheduling problems could be formulated as standard semidefinite programming (SDP) problems and solved by off-the-shelf solvers. Numerical results are provided to validate our analysis. The proposed methods and analyses provide meaningful insights for performance benchmarks for the implementation of SAGILN.

Compact quadband two-port antenna with metamaterial cell-inspired decoupling parasitic element for mobile wireless applications

Abstract In this paper, a quadband MIMO diamond-shaped antenna with two highly isolated elements is proposed and discussed. A novel metamaterial cell-inspired decoupling parasitic structure is deployed between the two antenna elements to achieve high isolation greater than 20 dB in the frequency bands of interest. Moreover, the design adopts a defected ground structure and open-ended multiple diamond-shaped branches for multiband characteristics, enabling the proposed MIMO to cover several modern wireless applications. The performance metrics of the proposed MIMO antenna are validated by evaluating various diversity parameters such as envelope correlation coefficient (ECC), diversity gain (DG), total active reflection coefficient (TARC), and channel capacity loss (CCL). This antenna is fabricated on an FR4 substrate with a compact size of 12 × 30 × 1.524 mm (0.082λ 0 × 0.204λ 0 × 0.001λ 0, λ 0 is the wavelength at 2.04 GHz). With the edge-to-edge separation distance of 0.053λ 0 between the antenna elements, its prototype is experimentally measured using a two-port Rohde &amp; Schwarz ZVA50 Vector Network Analyzer. The port-to-port isolation is about −20.87 dB, −23 dB, −25.93 dB, and −25.22 dB for 2.3 GHz, 3.18 GHz, 4.08 GHz, and 5.42 GHz frequency bands, respectively. Also, the proposed MIMO antenna exhibits good diversity performances with the ECC &lt; 0.005, DG &gt; 9.99, and TARC&lt;−10 dB making it an outstanding candidate covering 4G/LTE, 5G NR sub-6 GHz n40/n41/n77/n78, Wi-Fi, WiMAX, ISM, WBAN, Bluetooth, MBAN, WiBro, C-V2X, and UWB applications.

A New Design Approach for a Compact Microstrip Diplexer with Good Passband Characteristics

This paper presents an efficient theoretical design approach of a very compact microstrip diplexer for modern wireless communication system applications. The proposed basic resonator is made of coupled lines, simple transmission line and a shunt stub. The coupled lines and transmission line make a U-shape resonator while the shunt stub is loaded inside the U-shape cell to save the size significantly, where the overall size of the presented diplexer is only 0.008 λg2 . The configuration of this resonator is analyzed to increase intuitive understanding of the structure and easier optimization. The first and second resonance frequencies are f o1 = 895 MHz and f o2 = 2.2 GHz. Both channels have good properties so that the best simulated insertion loss at the first channel (0.075 dB) and the best simulated common port return losses at both channels (40.3 dB and 31.77 dB) are achieved. The presented diplexer can suppress the harmonics acceptably up to 3 GHz (3.3 fo1 ). Another feature is having 31% fractional bandwidth at the first channel.

Improving link failure restoration in next-generation wireless sensor networks

Next-generation wireless sensor networks (xWSN) have applications in many emerging wireless technologies, such as fifth-generation, internet-of-things, device-to-device communications, e-health, e-agriculture, etc. For most of these xWSN applications, network reliability and robustness against failures are crucial considerations. In this paper, an appropriate network restoration model is developed to help achieve network protection and/or restoration for xWSN in the event of link failures. In the model, effective network restoration is achieved by investigating efficient pre-configured-cycle (p-cycle)-based restoration solutions for the xWSN. Furthermore, to achieve significant improvement in the capacity efficiency of the p-cycle solutions realised, the concepts of p-cycle selectivity, load redistribution and the use of single p-cycles for double failure restoration are investigated and incorporated in the network restoration design. The restoration model developed, alongside the various improvement concepts incorporated, is shown to achieve better performance in terms of average path length and total capacity cost when compared with similar restoration models for modern wireless communication applications.

High gain wideband and multi-band on-demand reconfigurable antenna for modern wireless application

AbstractThis paper proposes a wide band and multiband frequency reconfigurable antenna that can operate in the UWB, GSM, GPS, 4G LTE, WLAN, and WiMAX bands. The antenna is made up of a trapezoidal-shaped monopole radiator, which was inspired by a rectangular monopole antenna. The ground plane is modified by embedding T and L-shaped slots to notch the desired operating frequency. The proposed antenna can switch to six different frequencies using RF PIN diodes, making it suitable for modern wireless applications. A multilayer frequency selective surface (FSS) reflector is presented to improve the gain of the proposed reconfigurable antenna. The low-profile design achieved a significant increase in gain while retaining the UWB antenna's excellent impedance bandwidth. Because of the use of the FSS reflector, the antenna's average peak gain has increased from 6 to 10.4 dBi. The proposed antenna has a wide switching capability, which validates its unique feasibility for high-speed multiple Internet of Things applications via a common embedded platform under various applications.

Design of multiple-input and multiple-output antenna for modern wireless applications

In this paper, multiple-input and multiple-output (MIMO) antennas are designed and simulated. The designed antennas are compact double-sided printed microstrip patch antennas and fed by a microstrip line. These antennas are designed for 3.5 to 10 GHz frequencies used for medical, industrial, sciences, and various fields of 5G communications and networking applications. Furthermore, a MIMO system is designed using the polarization variability of the individual antennas, which yields better results in terms of mutual coupling (S12 and S21), reflection coefficient (S11 and S22), and voltage standing wave ratio (VSWR), which is less than 2 indicate improved matching conditions. The designed antennas showed an acceptable gain (around 2 dB) and an envelope correlation coefficient (ECC) is &lt;0.002. In addition, the proposed MIMO antennas exhibited isolation is -25 dB at 6 GHz, which is preferable in 5G mobile antennas.

On the Relation Between Beam Coupling and Feed Coupling in Wideband Antenna Arrays

We present a study on beam coupling in radiating structures that support multiple simultaneous beams. The formation of multiple beams is relevant in modern wireless communication applications when diverse data streams can be sent from a single transmitter to users located in different directions. General expressions are provided that relate the coupling between radiated beams to the associated current distributions on the radiating aperture. When expanding the currents in terms of basis functions, the beam coupling can be also written in terms of coupling contributions due to each pair of basis functions. The analysis is applied to antenna arrays with different levels of mutual coupling between the array elements. More specifically, arrays of resonant elements, characterized by very low mutual coupling, are compared with arrays of connected elements, which are strongly coupled. We show that, even for a very high level of mutual coupling between individual array elements, it is possible to obtain orthogonal beams if the total current distributions associated with the beams are uncoupled.

A compact dual-band patch coupler design for modern wireless applications

This paper presents a compact rectangular patch hybrid coupler design which can be operated at dual resonant frequencies and is suitable for modern wireless applications. The dual-band functionality while maintaining practical compactness is achieved by introducing a series of parallel rectangular slots. The proposed design is optimized by the CST studio suite software and etched on the FR4 substrate. The good agreement between the simulated and measured frequency responses indicate that the presented coupler is capable of operating from 2.44 GHz to 3.1 GHz and from 5 GHz to 5.8 GHz, with fractional bandwidth of 24.44% and 14.8%, respectively, and a size reduction of 56.28%. The robust simulation results indicate that the proposed design is suitable for microwave integrated circuits (ICs) that require small size and dual functionality.