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A simple and compact polarization reconfigurable patch antenna design is proposed to operate in WLAN band at a resonant frequency of 2.4 GHz. This antenna consists of a rectangular patch placed on an FR4 substrate. A rectangular slot is cut in the rectangular patch. Two L shaped microstrip strips are placed inside the slot and joined together at the centre of the rectangular patch by inverting the L shaped microstrip. There are three different methods of achieving the reconfigurability namely electrical, mechanical and optical. This proposed structure uses electrical reconfiguration technique. This proposed antenna structure uses PIN diodes for achieving the polarization reconfigurability because of its ease in biasing. Two PIN diodes both being placed on the inverted L shaped structure in order to achieve the polarization modes and these PIN diodes are used to connect this microstrip with the rectangular patch. By switching these two PIN diodes for various biasing conditions, four different polarization modes namely two linear polarization (LP) modes, one Left Hand Circular polarization (LHCP) and one Right Hand Circular polarization (RHCP) mode is achieved. The antenna produces simulated gain of around 1.5416 dB for LP1 mode at 2.41 GHz, 1.7175 dB for LP2 mode at 2.45 GHz, 1.6062 dB for RHCP mode and 1.5922 dB for LHCP mode both at 2.4 GHz. The antenna structure is simulated using Ansys HFSS. [ABSTRACT FROM AUTHOR]

This research presents an innovative dual-band microstrip patch antenna design enhanced with defected ground structures (DGS) and barium strontium titanate (BST) thin film, tailored for wireless local area network (WLAN) and WiMax applications. The first design phase involved the development of an microstrip patch antenna (MPA) using an flame retardant (FR4) substrate with a permittivity (er1) of 4.3 and a thickness of 1.524 mm, enhanced with DGS. This configuration achieved a single-band resonance at 4.1 GHz, with a bandwidth of 0.82 GHz and a return loss (S11) of -32 dB. The second phase involved the integration of a BST thin film, with a high permittivity(er2) of 250 and a thickness of 0.1 mm, into the DGS-enhanced microstrip patch antenna (MPA). This modification led to a transformation in the antenna's performance, enabling dual-band operation at resonance frequencies of 2.8 GHz and 5.8 GHz. Further, there was a corresponding substantial increase in bandwidth to 1.34 GHz and 1.25 GHz, respectively, an improvement in S11 values to -16.3 dB and -21.4 dB. Moreover, and antenna's size of 14×10×1.524 mm³. The study underscores the critical role of innovative material use and design optimization in advancing antenna technology, offering significant enhancements in bandwidth, and miniaturization, for wireless communication systems. [ABSTRACT FROM AUTHOR]

This study uses annular circular rings to create multi-band applications using crescent-shaped patch antennas. It is designed to be made up of five circular, annular rings nested inside of each other. Three annular rings are positioned and merged on top of the larger rings, with two annular rings set along the bottom of the feed line. The factors that set them apart, such as bandwidths, radiation patterns, gain, impedance, and return loss (RL), are analysed. The outcomes show how compact the multi-band annular ring antenna is. The proposed circular annular ring antenna has return losses of −33 dB and operates at two frequencies: 3.1 GHz and 9.3 GHz. This design is modelled and simulated using ANSYS HFSS. The outcomes of the simulation and the tests agree quite well. The X band and WLAN resonant bands have bandwidth capacities of 500 and 4300 MHz, respectively. Additionally, the circular annular ring antenna design is advantageous for most services at these operating bands. [ABSTRACT FROM AUTHOR]

A novel, compact, monopole apple-shaped, triple-band metamaterial-printed wearable antenna backed by a uniplanar compact electromagnetic bandgap (UC-EBG) structure is introduced in this paper for wearable wireless and medical body area network (WBAN/MBAN) applications. A tri-band UC-EBG structure has been utilized as a ground plane to minimize the impact of antenna radiation on the human body and improve antenna performance for the proposed wearable antenna. Metamaterial triangular complementary split ring resonators (TCSRRs) are incorporated into the antenna and UC-EBG structure, resulting in a compact UC-EBG-backed antenna with an overall size of 39 × 39 × 2.84 mm3 (0.41 λg × 0.41 λg × 0.029 λg). The printed textile antenna operates at 2.45 GHz for the wireless local area network (WLAN), 3.5 GHz for 5G new radio (NR), and 5.8 GHz for the industrial, scientific, and medical (ISM) bands with improved gain and high-efficiency values. Furthermore, the performance of the antenna is analyzed on the human body, where three models of curved body parts are considered: a child's arm (worst case) with a 40 mm radius, an adult's arm with a 60 mm radius, and an adult's leg with a 70 mm radius. The results demonstrate that the proposed antenna is an attractive candidate for wearable healthcare and fitness monitoring devices and other WBAN/MBAN applications due to its compact size, high performance, and low SAR values. [ABSTRACT FROM AUTHOR]

This article presents a compact dual-band patch antenna designed for wireless communication systems. The proposed antenna design operates efficiently at both 2.45 GHz and 5.76 GHz achieving high performance despite its compact size. The Defected Microstrip Structure (DMS) is used to create the desired frequency bands and improve the impedance matching at the respective required frequencies, respectively. The antenna is manufactured on a low-cost FR-4 substrate, with dimension of 27 mm × 27 mm × 1.6 mm. The simulated radiation efficiencies at 2.45 GHz and5.76 GHz are 95% and 73%, respectively. In addition, the gain of the suggested antenna is more than 2.65 dB and around 2.84 dB at the desired frequency bands. The suggested antenna is simulated, manufactured, tested and verified practically. The return losses measured in the lower and upper resonance bands are 29.94% (covering the frequency range 2.13 to 2.88 GHz) and 6.2% (covering 5.65 to 6.01 GHz), respectively. The radiation pattern is measured and compared with simulation one. The design is simple, easy to carry on and is very compact, while enabling seamless operation across two different frequency bands, make it suitable for diverse wireless applications. [JJCIT 2024; 10(4.000): 383-392]

With the wide applications of the Internet of Things (IoT) in smart home systems, IEEE 802.11n Wireless Local Area Networks (WLANs) have become a frequently chosen communication technology due to their adaptability and affordability. In a high-density network of devices such as the smart home scenerio, a host often meets interferences from other devices and unequal Received Signal Strength (RSS) from Access Points (APs). This results in throughput unfairness/insufficiency problems between hosts communicating concurrently in WLAN. Previously, we have studied the throughput request satisfaction method to address this problem. It calculates the target throughput from measured single and concurrent throughputs of hosts and controls the actual throughput at this target one by applying traffic shaping at the AP. However, the insufficiency problem of maximizing the throughput is not solved due to interferences from other hosts. In this paper, we present an extension of the throughput request satisfaction method to maximize the throughput of a high-priority host under concurrent communications. It recalculates the target throughput to increase the actual throughput as much as possible while the other hosts satisfy the least throughput. For evaluations, we conduct experiments using the test-bed system with Raspberry Pi as the AP devices in several topologies in indoor environments. The results confirm the effectiveness of our proposal. [ABSTRACT FROM AUTHOR]

In this paper, a reconfigurable 2×2 and 4×4 MIMO antenna is designed for UWB X-band wireless applications. The proposed design uses square patch radiating electromagnetic energy and a novel ground structure and consists of a reconfigurable module enabling to set the operating mode using PIN diodes. The antenna allows rejecting 5 GHz WLAN and 7 GHz DSS interference by introducing “Γ-T” shape type stubs embedded on the radiating patch. The proposed design has reconfigurable features by using RF PIN diodes switch controlled by embedded module. Analysis of the proposed structure’s performance shows a good agreement between simulated results and actual outcomes measured in real-worlds scenarios. [ABSTRACT FROM AUTHOR]

This article presents a compact reconfigurable antenna capable of wide-band, dual-band operation. The proposed antenna is having two closed rings with ELC integration in the inner ring. The entire structure is designed and fabricated on a FR4 substrate with the foot print area of 30 × 31 mm2. Initially, a circular ELC-based monopole antenna operating within the frequency range of 2.4 - 2.7 GHz is described. By integrating two p-i-n diodes between the rings and ELC, distinct operating frequency bands are achieved through toggling the diodes. With one diode active, the antenna functions at 2.4 - 2.7 GHz and 4.2 - 4.3 GHz. Activating both diodes extends the bandwidth, enabling operation within the same frequency ranges. The bandwidth of 3200 and 98 MHz is achived in both the bands respectiveley. The gain of the proposed antenna is maintained above 2.0 dBi in the entire operating frequency range. The antenna's compact design, suitable for WiMAX and WLAN applications, is emphasized, and a comparison with contemporary designs underscores its size efficiency and versatile operational modes.

This article proposes a new approach to designing dipole antennas that can create circular polarization. Using a meander-shaped parasitic element in the upper part of the dipole forms a Yagi-Uda-like structure, and the cooperation between the dipole and the parasitic element leads to the production of circular polarization. The main contribution of this work is introducing a new technique for generating circular polarization using dipole antennas. This simple technique leads to a low-profile structure and has provided satisfactory results. Furthermore, by using the introduced CP antenna in a $4\times 4$ array structure and by stimulating a sequentially rotated feeding network, the impedance bandwidth of the antenna is improved, circular polarization with higher purity is achieved, and high radiation gain is achieved. Experimental results approve that the proposed array antenna has an impedance bandwidth of 1.66–3.29 GHz and covers the 1.76–3.12 GHz range with circular polarization. The overall dimension of the proposed array antenna is ( $0.78\times 0.78 \times 0.13$ ) $\lambda ^{3}$ , and a peak gain equal to 11.48 dB was reported for this work.

A novel wireless local area network (WLAN) antenna with dual-polarized and beam-reconfigurable ability is developed for WLAN 2.4 GHz band application. The antenna is composed of a horizontally polarized (HP) antenna and a vertically polarized (VP) antenna. The radiation pattern of the HP antenna can be switched between an omnidirectional beam and four directional beams in the azimuth plane, while the VP antenna can generate an omnidirectional beam and eight directional beams. Then the antenna prototype is fabricated and measured. The directional beam gain of the HP antenna varies from 2.7 to 3 dBi, and that of the VP antenna varies from 2.5 to 3.5 dBi. The maximum difference between the measured and simulated directional beams is 0.9 dBi. The measured and simulated reflection coefficients of the antenna are below −10 dB for all the beam states, and the isolation between the two polarizations is less than −18 dB in the WLAN 2.4 GHz band. The measured results agree well with the simulated ones, showing a good application prospect in WLAN system in the future.

This paper proposes a multi-band coupled-fed antenna (MBCFA) design for 4G LTE, Sub-6G, and WLAN frequencies, suitable for electronic devices with different sizes and fully metallic backplates. The MBCFA structure can be replicated on the fully metallic backplates of laptops, tablets, or smartphones to form a multi-input multi-output (MIMO) antenna system. Each MBCFA at different positions on laptops and tablets exhibits similar resonance characteristics, highlighting its high robustness and stability. The proposed MBCFA is manufactured using low-cost FR4 material. The overall size of MBCFA is 70 mm $\times12.5$ mm and an FR4 thickness of 0.8 mm, the measured reflection losses within the -6dB range are 740–990 MHz (250 MHz bandwidth), 1380–2640 MHz (1260 MHz bandwidth), and 4250–7330 MHz (3080 MHz bandwidth). The MBCFA’s isolation levels in the 4G LTE frequency band are below -16 dB, while the remaining frequency bands have isolation levels below -20 dB. The maximum antenna gain is approximately 5 dBi, and the optimal antenna efficiency is 60%. The Equivalent Coupling Coefficient (ECC) for all frequency bands is below 0.5. Given the excellent antenna characteristics described above, the proposed multi-band coupled-fed antenna is an outstanding candidate for laptop, tablet, and smartphone antennas.

This article demonstrates a portable ultrawideband (UWB) diversity antenna with capability of rejecting WLAN band. A circular split ring resonator (SRR) slot is etched out in the patch for filtering out the interference due to WLAN band centered at 5.2 GHz. A partial common ground plane with T-shaped stub is employed for high isolation. A fair correlation is reported between the simulated and experimentally measured findings with |S11| < −10 dB in the operational band. The measured isolation of |S21| < −20 dB along with satisfactory diversity performance metrics prove the utility of suggested antenna for UWB MIMO applications. [ABSTRACT FROM AUTHOR]

This paper will propose an innovative compact, lowcost, low-profile inverted U-shaped patch antenna with a single and dual band-notched ultra-wideband (UWB) with split ring resonators (SRRs). To achieve our main goal based on the reduction of electromagnetic interference in narrowband communications (WLAN, WiMAX, and satellite), four-element rectangular split-ring resonators (SRRs) array are placed nearby the feedline to create notch band at approximately 5.15-5.35 and 5.725-5.85 GHz. The SRRs antenna's measured data indicate a directivity of 8.52 dBi, a gain of 7.18 dBi, a reflection coefficient of -27 dB, and an efficiency of 84.3%. The realized prototype, including the SRRs and CSRRs structures, were carried out using a PCB prototyping machine. Reflection coefficient measurement is obtained using a vector network analyzer (VNA) PNA-X from Agilent Technologies. The measured values of the proposed antenna, with 50 x 38 x 1.6 mm3 in total and constructed on a FR4 substrate with permittivity of er = 4.3, loss tand = 0.0024 and substrate thickness of h = 1.6 mm, correlate well with the simulated values. The proposed antenna, compared with other published work, is a good candidate to operate in WLAN, X-band. [ABSTRACT FROM AUTHOR]

A compact horn-slotted coplanar waveguide (CPW) fed dual-band dual-sense circular polarization antenna is proposed. The antenna resonates with right-handed circular polarization in the lower frequency band and left-handed circular polarization in the upper frequency band. It has a novel horn-shaped slot and a CPW-fed inverted L-shaped active patch. The inverted L-shaped patch with a slanted stub at its right side provides dual-band dual-sense circular polarization characteristics. It has a compact geometry of 0.27 λ0 × 0.27 λ0 × 0.017 λ0, with wideband circular polarization characteristics extending from 2.92 to 3.67 GHz (22.82% of ARBW) and 5.2–5.73 GHz (9.5% of ARBW), thereby covering 5G and WLAN applications, respectively. [ABSTRACT FROM AUTHOR]

The role of antennas in wireless communication is critical for enabling efficient signal transmission and reception across various frequency bands, including those associated with IoT (Internet of Things), X-band, S-band, and RFID (radio-frequency identification) systems. This paper presents a small quadruple-band antenna with 25 × 40 × 1.5 mm3 dimensions designed for diverse wireless applications. It is adept at operating in the S-band (2.2 GHz), wireless local area network (WLAN) (5.7 GHz), microwave RFID frequency band (5.8 GHz), and X-band (7.7 GHz and 8.3 GHz). While the majority of existing research focuses on antennas covering two or three bands, our work stands out by achieving quad-band operation in the proposed antenna design. This antenna is constructed on a semiflexible Rogers RT5880 substrate, making it well-suited for wearable applications. Computer Simulation Technology (CST) Microwave studio (2019) simulation package software is chosen for design and analysis. The antenna design features a comb-shaped radiating structure, where each "tooth" is responsible for resonating at a distinct frequency with an appropriate bandwidth. The antenna retains stability in both free space and on-body wearability scenarios. It achieves a low specific absorption rate (SAR), meeting wearable criteria with SAR values below 1.6 W/Kg for all resonating frequencies. The proposed antenna demonstrates suitable radiation efficiency, reaching a maximum of 82.6% and a peak gain of 6.3 dBi. It exhibits a bidirectional pattern in the elevation plane and omnidirectional behavior in the azimuth plane. The antenna finds applications across multiple frequencies and shows close agreement between simulated and measured results, validating its effectiveness. [ABSTRACT FROM AUTHOR]

The co-integration of antennas with lighting sources appears as an effective way to distribute broadband networks closer to users, lowering interference and transmitted power, as well as to reduce energy consumption in future lighting systems. We here present an original contribution to the implementation of transparent and invisible antennas with OLED light sources. To validate the proposed approach, the honeycomb mesh technique was used, and an optical transparency of 75.4% was reached. The transparent mesh antenna was compared with the non-transparent full-metal antenna in terms of radio-electrical parameters. Our prototype was designed using copper films deposited on a glass substrate. The simulation results of the S-parameters and the radiation patterns were validated against measurements performed in an anechoic chamber. The directivity and gain obtained were 6.67 dBi and 4.86 dBi at 5.16 G Hz , respectively. To study the effect of antenna integration with OLEDs, optical and photometric characterizations with and without the antenna were measured, and the colorimetric parameters were then treated using the IES TM-30-18 standard. [ABSTRACT FROM AUTHOR]

This letter presents a compact slotted pentaband inset-fed microstrip antenna designed to operate for UMTS, WLAN, WiMAX, C-band and X-band applications. By incorporating equispaced slots of same width and length and also the inset feeding, the antenna generates five bands, allowing for penta-band operation. The antenna is manufactured on an FR4 substrate and is excited by an SMA connector using a microstrip line. With its compact dimensions of 25x25x1.6 mm3, the antenna offers a simple structure. Based on the simulated and measured outcomes, the proposed antenna demonstrates numerous advantages, making it highly suitable for wireless communication systems. These advantages include its ability to operate in multiple bands, its percentage bandwidth, compact size, stable radiation pattern, ease of processing, and costeffectiveness. [ABSTRACT FROM AUTHOR]

Information security is a significant viewpoint in different areas of correspondence. This paper manages information encryption as large numbers of data correspondence rely upon encryption information. In this paper, another proposition of an information encryption framework has been presented. The framework can be partitioned into two stages; the primary stage centers around creating a top-notch Pseudo Irregular Number generator PRNGs utilizing rudimentary, intermittent, and crossover rules of cell automata CA. The framework recommends another mix of CA rules in an undertaking to give high arbitrariness and to work on the strength of the proposed cryptosystem. The subsequent stage creates the Improved Rivest Code 5 ERC5 calculations which utilizes the produced arbitrary Number Succession RNS with an end goal to reinforce the security and haphazardness of the first Rivest Code 5 RC5 Algorithm. The outcomes show that the proposed PRNGs in light of CA can create RNS with a high period which can reach more than 100000 keys without reiteration or string duplication. In addition, the test exhibits that the proposed ERC5 works on the security of the first RC5 calculation. The proposed cryptosystem is assessed as far as Shannon's hypothesis of data entropy, irregularity tests, calculation time, and key space investigation. The outcomes confirm that the recommended information crypto-framework expands the development of the security level of unique RC5 encryption calculation with a serious level of arbitrariness and privacy. It is executed this work to show the results rely upon the programming language C# and the correspondence was presented in a structure called disseminated through an association wireless local-area network WIFI.

This paper describes the design and analysis of a reconfigurable radiation pattern dual-band antenna for Wi-Fi and WLAN applications. The antenna patch comprises two parts: the upper part, which consists of three symmetrical oval rings, and the lower part, which is shaped like a lotus flower. By controlling the ON and OFF states of lumped p-i-n switches to control the direction of the radiation beams, the proposed pattern reconfigurable antenna achieves three reconfigurable states. The beam's direction change is performed by two switches that are connected in the gap between the feedline and the arch. The proposed antenna operates at 2.4 and 5.5 GHz, covering the bands from 2.1882 to 2.55 GHz and from 5.31 to 5.96 GHz, respectively. Additionally, the directivity over the working bands is about 1.92 to 4 dBi while the gain lies in the range of 1.66 to 3.5 dB. Moreover, the voltage standing wave ratio (VSWR) varies from 1 to 1.20. The size of the antenna is 47×59.5 mm2 which is printed on a 1.6 mm thickness FR-4 substrate of 4.4 relative permittivity. Computer simulation technology Microwave Studio is used to design and study the recommended constructions. The proposed design achieves an acceptable value of VSWR, stable gain, and good directivity, which makes it a suitable choice for future radiation pattern reconfiguration applications. The proposed antenna is distinguished by a simple shape, compact size, respectable return loss, good radiation characteristics, and high efficiency. The obtained results from measurements are quite close to the simulations.

In this paper, a reconfigurable 2×2 and 4×4 MIMO antenna is designed for UWB X-band wireless applications. The proposed design uses square patch radiating electromagnetic energy and a novel ground structure and consists of a reconfigurable module enabling to set the operating mode using PIN diodes. The antenna allows rejecting 5 GHz WLAN and 7 GHz DSS interference by introducing "Γ-T" shape type stubs embedded on the radiating patch. The proposed design has reconfigurable features by using RF PIN diodes switch controlled by embedded module. Analysis of the proposed structure's performance shows a good agreement between simulated results and actual outcomes measured in real-worlds scenarios.

MIMO antenna design has always been a topic of interest in wireless technology. Although it has many benefits, the key challenge is to minimize mutual coupling between antenna elements. This study presents a decoupling technique between two tri-band antennas for LTE, WLAN, and 5G applications. For 3.5GHz, a monopole is initially created; the other two resonant frequencies are produced by changing the partial ground plane. Then, a MIMO antenna system is created using two tri-band monopoles. The resonators of low band can minimize the mutual coupling for two higher bands by suppressing surface wave propagation. Finally, coupling is reduced in the low band by using a Split Ring Resonator (SRR) to cancel out the original coupling. The reported MIMO antenna spans the 2.4/5.8GHz WLAN and LTE bands, as well as the 3.5 GHz 5G bands, with a mutual coupling of less than -18 dB.

This article reports the Modified Microstrip Feed Hybrid Rectangular Dielectric Resonator Antenna (RDRA). The proposed structure has a ground plane with a plus-shaped slot on an FR4 substrate with a height of 1.6 mm and dimensions of 38 mm x 35 mm. The proposed Dielectric resonator antenna is made of a material with 10 as its dielectric constant, and the dimensions of the DR are 19 x 20 x 18 mm3. The DR is connected to a modified microstrip feed with an octagonal ring through the plus-shaped slot in the ground. The proposed structure operates in frequencies from 2.60 GHz - 2.74 GHz, 3.12 GHz - 3.37 GHz, and 4.25 GHz - 4.37 GHz. The resonant frequency of the final proposed RDRA is 2.68 GHz, 3.26 GHz, and 4.31 GHz, which covers WLAN, WIMAX and Wireless Avionics Intra-Communications (WAIC) applications, respectively. The entire structure was simulated using the CST microwave studio. The simulated results agree with the measured results and both are presented. The compact size, stable radiation pattern and reasonable gain make this antenna suitable for the proposed applications.

The traditional live video transmission optimization mechanism is deployed on the server side, which cannot quickly respond to the dynamic changes of the user’s wireless network environment.To address this problem, a live video transmission optimization mechanism based on edge intelligence called S-Edge was proposed.It was deployed on the OpenWrt-based wireless access point, and comprehensively utilized the wireless channel state information such as airtime utilization and signal-to-noise ratio to make intelligent decisions on terminal priority and transmission rate based on fuzzy logic theory.Furthermore, the active queue management with hierarchical token bucket and service demand-driven wireless transmission rate adaptive control technologies were introduced to realize the real-time scheduling of live video data.In order to verify the effectiveness and performance of the proposed mechanism, a high client-density environment was built through user clusters based on multi-radio interfaces in the real-world scenario.Experimental results show that S-Edge can significantly reduce the average delay and packet loss rate, which meets QoS requirements of live video transmission services in the high client-density environment.

With the rapid development and wide applications of information and communication technologies, human production and life and social governance are evolving in the direction of digitizing, informatization, and intelligence.As one of the most widely applied wireless communication technologies, the wireless local area network (WLAN) needs to make further breakthroughs in the key performance such as data throughput, reliability, and latency and needs to add sensing functions and intelligence.The huge frequency resources of the millimeter wave (mmWave) band have injected new momentum into the development of WLAN.But the mmWave WLAN has also brought new technical challenges and requirements.Firstly, the WLAN development history was reviewed, and network structures, typical applications, development directions, and performance index requirements of WLAN in the future were summarized.Then, the characteristics of wireless channels in the mmWave band were given, and the new requirements and challenges for mmWave WLAN design were analyzed.Finally, some potential key technologies that may meet these challenges and requirements were discussed and prospected.

Abstract This paper will propose an innovative compact, low-cost, low-profile inverted U-shaped patch antenna with a single and dual band-notched ultra-wideband (UWB) with split ring resonators (SRRs). To achieve our main goal based on the reduction of electromagnetic interference in narrowband communications (WLAN, WiMAX, and satellite), four-element rectangular split-ring resonators (SRRs) array are placed nearby the feedline to create notch band at approximately 5.15-5.35 and 5.725-5.85 GHz. The SRRs antenna's measured data indicate a directivity of 8.52 dBi, a gain of 7.18 dBi, a reflection coefficient of -27 dB, and an efficiency of 84.3%. The realized prototype, including the SRRs and CSRRs structures, were carried out using a PCB prototyping machine. Reflection coefficient measurement is obtained using a vector network analyzer (VNA) PNA-X from Agilent Technologies. The measured values of the proposed antenna, with 50 x 38 x 1.6 mm3 in total and constructed on a FR4 substrate with permittivity of ɛr = 4.3, loss tanδ = 0.0024 and substrate thickness of h = 1.6 mm, correlate well with the simulated values. The proposed antenna, compared with other published work, is a good candidate to operate in WLAN, X-band.

This study developed a metamaterial-inspired split-ring resonator (SRR) based inversion symmetry-shaped structure for airport surveillance radar and local area wireless network applications. The proposed device exhibited suitability for S- and C-band applications, featuring distinct resonance peaks at 2.8 and 4.9 GHz, respectively. The two-layer double negative metamaterial unit cell comprises a copper-based resonator, patch, and a low-loss substrate material known as Rogers RT5800 with a thickness of 1.575 mm. The 8 × 8 mm2 structure unit cell was identified with an effective medium ratio (EMR) of 13.4 at the resonance peak of 2.8 GHz. With the alteration of the metamaterial unit cell structure, the electric field, surface current distribution, magnetic field, and design evolution were observed, analysed, and investigated in this study. Meanwhile, the retrieved data from the reflection and transmission coefficients from CST Microwave Studio were validated using the Ansys High-Frequency Structure Simulator (HFSS) software. A Vector Network Analyzer (VNA) further measured the numerical results. Based on the findings, the proposed novel double negative metamaterial device is suitable for radar communication and satellite applications, especially airport surveillance radar (ASR) and wireless local area network (WLAN), due to its high EMR at the desired resonance frequency.

This paper proposes an eight-element dual-band multiple-input multiple-output (MIMO) antenna that operates in the fifth generation (5G), n78 (3400–3600 MHz), and WLAN (5275–5850 MHz) bands to accommodate the usage scenarios of 5G mobile phones. The eight antenna elements are printed on two long frames, which significantly reduce the usage of the internal space of the mobile phone. Each antenna element is printed on both surfaces of one frame, which consists of a radiator on the internal surface and a defected ground plane on the outer surface. The radiator is a rectangular ring fed by a 50 Ω microstrip line which is printed on the top surface of the system board. A parasitic unit is printed on the outer surface of each frame, which is composed of an inverted H-shaped and four L-shaped patches. Each parasitic unit is connected to the internal surface of the frames through a via, and then it is connected to a 1.5 mm wide microstrip line on the top surface of the system board, which is connected to the ground plane on the bottom surface of the system board by a via. Four L-shaped slots, four rectangular slots, and four U-shaped slots are etched onto the system board, which provides good isolation between the antenna elements. Two merged rectangular rings are printed on the center of each frame, which improves the isolation further. The return loss is better than 6 dB, and the isolation between the units is better than 15 dB in the required working frequency bands. In addition, the use of a defected ground structure not only makes the antenna element obtain better isolation but also improves the overall working efficiency. The measurement results show that the proposed MIMO antenna structure can be an ideal solution for 5G and WLAN applications. [ABSTRACT FROM AUTHOR]

This study focuses on the design of a dual-band microstrip patch antenna, which is capable of operating in two different frequency bands, specifically the 4.9 GHz and 6.7 GHz WLAN (Wireless Local Area Network) bands. With the growing popularity of wireless communication technology and the ability to utilize frequency bands without the need for authorization, WLAN usage is becoming increasingly widespread. The design of the antenna is conducted using the High-Frequency Structure Simulator (HFSS) electromagnetic simulation software. The proposed antenna is made on a low-cost FR-4 substrate with a dielectric permittivity of 4.4, which offers benefits such as affordability and compactness. The resulting antenna has a compact size of 17.952 mm by 16.896 mm, including a substrate thickness of 1.6 mm, making it one of the smallest dual-band microstrip patch antenna. The antenna utilizes microstrip line feeding, and its radiating patch is formed by cutting inverted C-shaped from the patch and inverted U-shaped grooves from the feed line, allowing it to be compatible with 4.9 GHz and 6.7 GHz WLAN bands. The design and simulation results demonstrate that the proposed antenna has a dual-band capability and favorable transmission characteristics within its operating frequency range, meeting the demands of WLAN communication. [ABSTRACT FROM AUTHOR]

This article describes the development of a compact microstrip bandpass filter (BPF) for multiple wireless communication utilizations. The proposed bandpass filter consists of metamaterial unit cells that are symmetrical in shape. The design process involves the placement of four symmetrical split-ring resonators (SRRs) on the top plane of the BPF. It exhibits improved filter characteristics through the implementation of these SRRs. The filter was modeled and fabricated and its performance was evaluated using a Vector Network Analyzer. The designed bandpass filter shows a 5 GHz bandwidth covering the frequency band spanning from 1 to 5.2 GHz, with a quality factor value of 1.85 across 1.9 GHz, 3.3 across 3.3 GHz and 5.1 across 5.1 GHz. The metamaterial analysis was carried out using ANSYS ELECTRONIC DESKTOP. The proposed filter measures 20 × 18 × 1.6 mm3, which is significantly smaller than current filters. The designed bandpass filter occupies 50% of the space of a conventional filter. The designed bandpass filter exhibits a distributed surface current of 84 A/m, and 94 A/m across the wide- and narrow-band operating frequency. The simulated and measured results indicate that the suggested metamaterial filter is well-suited for multiband wireless applications like GPS (1.57 GHz), WLAN (2.4, 3.6, and 5.2 GHz), Wi-MAX (2.3, 2.5, and 3.5 GHz), and ISM (2.5 GHz). [ABSTRACT FROM AUTHOR]

A layer of metallic oxide is usually employed on one side of energy-saving glass (ESG) to pass the visible frequencies and to restrict the infrared (IR) waves. The technique increases the thermal efficiency of ESG; however, it attenuates the radio frequency (RF), and microwave (MW) signals due to the resistance of metallic oxide, thus mobile communication is significantly degraded. In this paper, transmission of RF and MW and IR frequencies through ESG has been investigated by etching band-pass frequency-selective surfaces (FSSs) in the ESG coating. However, the thermal efficiency of ESG decreases due to the etching of FSS. Thermal simulations have been conducted to investigate the heat efficiency of the FSS design. A band-pass FSS has been designed in the 0.1–3.5 GHz band which provides transmission improvement of up to 26 dB. Wireless Local Area Network (WLAN) security and confinement is also ensured for 4–6 GHz by restricting signals inside the building. The amount of area etched is minimized in order to avoid heat loss. The TE and TM polarization for normal and oblique angle of incidence up to 60° was achieved and verified through experimental results. Moreover, the thermal efficiency of ESG and the impact of band-pass FSS on ESG has also been investigated. WLAN security, RF/MW transmission improvement, transmission bandwidth, and thermal efficiency have all been significantly improved in comparison with state-of-the-art designs. Theoretical transmission results were obtained using ANSYS HFSS, and transmission of RF/MW signals has been verified through the measured results. Theoretical results for the thermal analysis of ESG have been obtained using COMSOL Multiphysics software. [ABSTRACT FROM AUTHOR]

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Security identification solutions against WLAN network attacks according to straightforward digital detectors, such as SSID, IP addresses, and MAC addresses, are not efficient in identifying such hacking or router impersonation. These detectors can be simply mocked. Therefore, a further protected key uses new information by combining these simple digital identifiers with an RF signature of the radio link. In this work, a design of a convolutional neural network (CNN) based on fingerprinting radio frequency (RF) is developed with computer-generated data. The developed CNN is trained with beacon frames of a wireless local area network (WLAN) that is simulated as a result of identified and unidentified router nodes of fingerprinting RF. The proposed CNN is able to detect router impersonators by comparing the data pair of the MAC address and RF signature of the received signal from the known and unknown routers. ADAM optimizer, which is the extended version of stochastic gradient descent, has been used with a developed deep learning convolutional neural network containing three fully connected and two convolutional layers. According to the training progress graphic, the network converges to around 100% accuracy within the first epoch, which indicates that the developed architecture was efficient in detecting router impersonations. [ABSTRACT FROM AUTHOR]

Sixth-generation (6G) mobile technology is currently under development, and is envisioned to fulfill the requirements of a fully connected world, providing ubiquitous wireless connectivity for diverse users and emerging applications. Transformative solutions are expected to drive the surge to accommodate a rapidly growing number of intelligent devices and services. In this regard, wireless local area networks (WLANs) have a major role to play in indoor spaces, from supporting explosive growth in high-bandwidth applications to massive sensor arrays with diverse network requirements. Sixth-generation technology is expected to have a superconvergence of networks, including WLANs, to support this growth in applications in multiple dimensions. To this end, this paper comprehensively reviews the latest developments in diverse WLAN technologies, including WiFi, visible light communication, and optical wireless communication networks, as well as their technical capabilities. This paper also discusses how well these emerging WLANs align with supporting 6G requirements. The analyses presented in the paper provide insight into the research opportunities that need to be investigated to overcome the challenges in integrating WLANs in a 6G ecosystem.

Abstract Due to the heavy workload of RSS collection, the instability of WLAN signal strength and the disappearance of signals caused by complex indoor environments, the construction of radio map for wireless local area network (WLAN) fingerprint-based indoor positioning system is time-consuming and laborious. In order to rapidly deploy indoor WLAN positioning system, the bidirectional encoder representation from transformers (BERT) model is used to fill the missing signal in radio map and quickly build radio map. The radio map is imported into the BERT model in the form of natural language text, and the missing signal is filled by the BERT model. Since the number of input data in BERT model cannot exceed 512 words, the structure of BERT model is not suitable for WLAN signals with large data volume. Therefore, we redefine the model structure based on the original BERT model and fill in the missing signals in the radio map in parallel. In addition, the loss function is redefined. Except that each segment has a loss function, the weighted average value of all segment loss functions is defined as the total loss function. The experimental results show that the BERT model is better than the traditional linear interpolation method, compressed sensing algorithm and matrix completion algorithm in filling the missing signals in the fingerprint database, and the probability of error within 2 m reaches about 94%.

Currently, Internet of Things (IoT) has become common in various applications, including smart factories, smart cities, and smart homes. In them, wireless local-area networks (WLANs) are widely used due to their high-speed data transfer, flexible coverage ranges, and low costs. To enhance the performance, the WLAN configuration should be optimized in dense WLAN environments where multiple access points (APs) and hosts exist. Previously, we have studied the active AP configuration algorithm for dual interfaces using IEEE802.11n and 11ac protocols at each AP under non-channel bonding (non-CB). In this paper, we study the algorithm considering the channel bonding (CB) to enhance its capacity by bonding two channels together. To improve the throughput estimation accuracy of the algorithm, the reduction factor is introduced at contending hosts for the same AP. For evaluations, we conducted extensive experiments using the WIMENT simulator and the testbed system using Raspberry Pi 4B APs. The results show that the estimated throughput is well matched with the measured one, and the proposal achieves the higher throughput with a smaller number of active APs than the previous configurations.

This study uses annular circular rings to create multi-band applications using crescent-shaped patch antennas. It is designed to be made up of five circular, annular rings nested inside of each other. Three annular rings are positioned and merged on top of the larger rings, with two annular rings set along the bottom of the feed line. The factors that set them apart, such as bandwidths, radiation patterns, gain, impedance, and return loss (RL), are analysed. The outcomes show how compact the multi-band annular ring antenna is. The proposed circular annular ring antenna has return losses of −33 dB and operates at two frequencies: 3.1 GHz and 9.3 GHz. This design is modelled and simulated using ANSYS HFSS. The outcomes of the simulation and the tests agree quite well. The X band and WLAN resonant bands have bandwidth capacities of 500 and 4300 MHz, respectively. Additionally, the circular annular ring antenna design is advantageous for most services at these operating bands.

This paper presents a planar CPW-fed Ultrawideband (UWB) antenna with two independently tunable notch bands. The proposed design consists of a modified Rhombus-shaped monopole structure that is integrated with a dual band-stop filter based on hexagonal split ring resonators (HSRR). The antenna is capable of suppressing multiple frequency bands within ultrawideband range (3.1–11 GHz) such as WLAN and X-band downlink satellite communication frequency bands with an independent tunable mechanism to fulfill the on-demand band rejection. The frequency reconfigurability of the two notch bands is obtained by loading the hexagonal filter arms with two varactor diodes (for each band). Details of antenna design steps and reconfigurability mechanism are illustrated. The notch band element is explained using equivalent circuit model and surface current distribution at lower and higher notch frequency bands. A prototype of the proposed design is printed on the RO4003C (ϵ r = 3.55) substrate printed circuit board (PCB) and tested to authenticate the performance. The proposed antenna volume is 21.5 ▪ 48 ▪ 1.524 mm3 and demonstrates an omnidirectional radiation pattern in E and H planes with an average gain of 3.7 dBi across the operational passbands, while a sharp reduction in gain of -6.8 dBi and -3.5 dBi is achieved at the lower and higher notch bands, respectively. Continuous tuning is achieved experimentally from 5.08 to 5.77 GHz and 7.75 to 8.52 GHz for the lower and higher notch bands, respectively. Excellent agreement is observed between the simulated and measured results. Application areas include radio-frequency identifications, ground-penetrating radar, and wireless communications. [ABSTRACT FROM AUTHOR]

A miniaturized and low-profile planar antenna is a crucial part of any wireless communication system. To cover additional narrowband services and to reduce system complexity, antennas in portable devices should offer several operating bands. In this paper, we propose a coplanar-waveguide-fed (CPW-fed), flexible, and compact slotted patch frequency reconfigurable antenna with a compact size of 20 × 24 mm 2 . The designed antenna employs a low-cost Rogers 5880 substrate with a thickness of 0.127 mm. This choice of substrate ensures cost-effectiveness while preserving the desired performance of the antenna. The antenna radiates through five distinct frequency bands, including 5.58–6.25 GHz, 6.05–8.81 GHz, 8.79–9.7 GHz, 9.7–10.22 GHz, and 10.48–15 GHz, depending on the switch on/off condition, thereby enabling the antenna to span a broader range of frequencies for WLAN, C-UWB, sub-6 GHz, and X-band communications. The designed antenna is fabricated and tested in both the on and off states. The measured results closely match the simulated outcomes. [ABSTRACT FROM AUTHOR]

The Industrial, Scientific, and Medical (ISM) frequency spectrum is used by the Wireless Local Area Network (WLAN) for its operation. Due to a limited number of available channels for WLAN operation, frequency channel assignment becomes very difficult. In WLAN, the access points (APs) are widely deployed, and because they share the same frequency, they start interfering with each other and causing more energy consumption. So WLAN frequency channels should be managed and assigned carefully to increase the energy efficiency of the wireless network. This paper proposes an energy-efficient channel assignment algorithm (EECAA) to improve the performance of the network. The suggested approach improves the network's energy efficiency in terms of global delay, packet data loss, and the count of data retransmissions. The extensive simulation study demonstrates that, when compared to the channel handoff scheme and D2MD channel allocation algorithm for various traffic and network conditions, the proposed EECAA method greatly increases network throughput. [ABSTRACT FROM AUTHOR]

A novel miniature wideband rectangular ring antenna is proposed for 4.6–6.2 GHz which is compatible with IoT applications. The wideband response of the proposed antenna is achieved by a partial ground and stair step structure. Because modifying the width and etching the ground plane does not improve the impedance matching over a large bandwidth, a triangular shape DGS is inserted in the partial ground plane to increase the antenna bandwidth with enhanced return loss. The wideband features of the antenna were explored here by incorporating different DGS shapes such as triangles, rectangle, pentagon, circle, and oval in the partial ground. The results have been successfully verified through measurement. The simulated fractional bandwidth is greater than 29% at 4.6–6.2 GHz whereas the measured fractional bandwidth is 27.6% at 4.75–6.2 GHz. In both cases, the maximum return loss is greater than 55 dB. The gain of the antenna is greater than 2.6 dB with good efficiency and nearly omnidirectional radiation pattern in shape. Due to its compact size and outstanding performance, the suggested stair step-shaped rectangular ring antenna could be a promising choice for IoT and wireless applications. [ABSTRACT FROM AUTHOR]

This communication presents a novel, low-profile coplanar waveguide (CPW)-fed dual-band microstrip antenna for wireless applications. The proposed antenna consists of an inverted L-shaped slot radiator coupled with a U-shaped ground plane and two vertical ground terminals. It is implemented on FR4-epoxy dielectric substrate material (εr = 4.4, tan δ = 0.02) with dimensions of 56 × 56 mm2 and generates two desired resonant frequencies at about 2.40 GHz and 3.48 GHz for WLAN and WiMAX applications, respectively. The antenna shows two distinct bands, first from 2.34 to 2.54 (200 MHz at −20 dB) and second from 3.25 to 3.60 (350 MHz at −12 dB), which cover the entire WLAN (fc = 2.4 GHz, 2.400–2.484 GHz) and WiMAX (fc = 3.5 GHz, 3.400–3.690 GHz) bands. This work aims to combine WLAN and WiMAX communication standards simultaneously into a single device by designing a single antenna that can excite dual-band operation. Also, numerical findings are presented for the antenna's return loss and 2D radiation patterns. Good agreement between measured and simulated outcomes is established. The results indicate that the proposed antenna, which performs well, may be appropriate for WLAN/WiMAX applications, including those involving portable electronics and emerging technologies. [ABSTRACT FROM AUTHOR]

In the era of continuous advancement in wireless technologies, path loss, also known as channel attenuation, is a drop in signal strength from the transmitter to the receiver. Path loss modelling is critical in designing fixed and mobile communication systems for various applications. This paper focuses on the received power (dBm) and free space path loss (FSPL) on various distances and frequencies such as 5240 MHz for wireless local area network (WLAN) and frequency such as 2100 MHz for the mobile network such as Celcom. As a result, able to analyze the correspondence between received power (dBm) and distance of each related frequency and the correspondence between FSPL (dB) and distance of each corresponding frequency and able to analyze the effect of obstacle on received power (dBm) and frequency.

In the paper, the BTS (Background Traffic Simulator) tool is proposed to capture network traffic and then reproduce it in a simulations using the ns-3 simulator extension module. This new method of generating background traffic allows for repetitive testing of simulation scenarios under real network conditions. The authors described the differences between the previously available methods and the proposed solution. The operation of all the most important elements of the proposed tool has been described. The influence of the generated background traffic on the simulation scenario was presented as well as the results of the operation.

A dual-band antenna is used for several wireless networks like ISM, WLAN, WiMAX, and WiFi. The antenna's uppermost element is a monopole shape with a rectangular protrusion. Antennas are created in CST. Using a 19-millimetre-wide by 31-millimetre-long FR4 substrate, the antenna is created in a design environment. Due to the SRR printing in the ground and the antenna's defective ground structure, the antenna is able to achieve dual resonance. A split ring resonator printed at the base also helps achieve a second resonance. With the help of a parameter analysis, we can pick the optimal proportions for the design. The antenna resonates at both 2.3 and 5.8 GHz. We construct and test the antenna. The results obtained through simulation are equivalent to those obtained from measurements in terms of s11, gain, and directivity, as well as E-plane and H-plane patterns. Because of its compact size, consistent radiation pattern, dual-band use, and excellent impedance matching and bandwidth, the suggested antenna is an excellent choice for use in ISM networks and other wireless applications.

A compact self-isolated four-element MIMO antenna is introduced for use in ISM systems and WLAN applications in the 2.4 GHz frequency band. The proposed design consists of four printed dipoles so four integrated baluns are responsible for feeding these antennas. By choosing an appropriate arrangement of the elements next to each other and using the feature of self-isolated antennas, great isolation is achieved in the first step. Finally, by utilizing a printed decoupling component in the space between the dipoles, the value of the envelope correlation coefficient (ECC) parameter comes very close to zero for the MIMO antenna. The major part of the isolation in this design is the responsibility of the self-isolated technique, and adding the decoupling element at the last stage of the design is to complete the antenna isolation process. The fabricated prototype of the proposed MIMO antenna operating at 2.25-2.87 GHz frequency band reaches the measured port-to-port isolation of better than 19 dB, ECC of less than 0.0009, the peak gain of 8.6 dBi with total dimensions of $1.11\lambda _{0}\times 1.11 \lambda _{0}\times 0.34\lambda _{0}$ . The numerical and experimental results approve the excellent MIMO performance for 2.4 GHz applications.

This paper introduces a new high-performance successive approximation register (SAR) analog-to-digital converter (ADC) designed for high-speed and low-power wireless local area network (WLAN) applications using a SMIC 55 nm 1p8m CMOS process. The design employs several innovative techniques, including an improved bootstrap switch with high linearity, a 4-reference voltage method to minimize capacitive digital-to-analog converter (CDAC) mismatch, a kickback-canceling comparator to eliminate kick-back noise, and redundant design-assisted window-opening SAR logic to decrease conversion time. Experimental results reveal that the proposed ADC achieves an impressive signal-to-noise and distortion ratio (SNDR) of 55.3 dB and a spurious-free dynamic range (SFDR) of 66.6 dB at a sampling rate of 200 MHz with Nyquist frequency input while consuming a power of 2.8 mW at a 1.2 V power supply. This corresponds to a figure-of-merit (FoM) value of 29 fJ/conversion-step. Thanks to the incorporation of the 4-reference voltage method, the ADC demonstrates a significant area advantage compared to other designs with similar FOM values utilizing more advanced processes, occupying a mere 0.008 mm2 of core area. [ABSTRACT FROM AUTHOR]

Sixth-generation (6G) mobile technology is currently under development, and is envisioned to fulfill the requirements of a fully connected world, providing ubiquitous wireless connectivity for diverse users and emerging applications. Transformative solutions are expected to drive the surge to accommodate a rapidly growing number of intelligent devices and services. In this regard, wireless local area networks (WLANs) have a major role to play in indoor spaces, from supporting explosive growth in high-bandwidth applications to massive sensor arrays with diverse network requirements. Sixth-generation technology is expected to have a superconvergence of networks, including WLANs, to support this growth in applications in multiple dimensions. To this end, this paper comprehensively reviews the latest developments in diverse WLAN technologies, including WiFi, visible light communication, and optical wireless communication networks, as well as their technical capabilities. This paper also discusses how well these emerging WLANs align with supporting 6G requirements. The analyses presented in the paper provide insight into the research opportunities that need to be investigated to overcome the challenges in integrating WLANs in a 6G ecosystem. [ABSTRACT FROM AUTHOR]

In this paper, a 12-port MIMO antenna system for 5G/WLAN applications is proposed. The proposed antenna system consists of two types of antenna modules: an L-shaped antenna module covering the C-band (3.4–3.6 GHz) for 5G mobile applications and a folded monopole module for the 5G/WLAN mobile application band (4.5–5.9 GHz). Each two antennas form a pair, six pairs in total, forming a 12 × 12 MIMO antenna array, and the elements between the antenna pairs can achieve an isolation of 11 dB or more without additional decoupling structures. Experimental results show that the antenna can cover the 3.3–3.6 GHz and 4.5–5.9 GHz bands with an overall efficiency greater than 75% and an envelope correlation coefficient less than 0.04. Finally, the one-hand holding mode and two-hand holding mode are discussed to demonstrate their stability in practical applications, and the results show that they still exhibit good radiation and MIMO performance when operating in both modes. [ABSTRACT FROM AUTHOR]