Wireless Local Area Network Applications Research Articles

A Low-Profile Antenna for On-Body and Off-Body Applications in the Lower and Upper ISM and WLAN Bands.

The article presents a Co-planar Waveguide (CPW) fed antenna of a low-profile, simple geometry, and compact size operating at the dual band for ISM and WLAN applications for 5G communication devices. The antenna has a small size of 30 mm × 18 mm × 0.79 mm and is realized using Rogers RT/Duroid 5880 substrate. The proposed dual-band antenna contains a CPW feedline along with the triangular patch. Later on, various stubs are loaded to obtain optimal results. The proposed antenna offers a dual band at 2.4 and 5.4 GHz while covering the impedance bandwidths of 2.25-2.8 GHz for ISM and 5.45-5.65 GHz for WLAN applications, respectively. The proposed antenna design is studied and analyzed using the Electromagnetic (EM) High-Frequency Structure Simulator (HFSSv9) tool, and a hardware prototype is fabricated to verify the simulated results. As the antenna is intended for on-body applications, therefore, Specific Absorption Rate (SAR) analysis is carried out to investigate the Electromagnetic effects of the antenna on the human body. Moreover, a comparison between the proposed dual-band antenna and other relevant works in the literature is presented. The results and comparison of the proposed work with other literary works validate that the proposed dual-band antenna is suitable for future 5G devices working in Industrial, Scientific, Medical (ISM), and Wireless Local Area Network (WLAN) bands.

A compact plus shaped with L-shaped slotted microstrip patch antenna for GSM, WLAN, WiMAX, C- and X- band applications

In this research article, a compact plus-shaped L-shaped slotted microstrip patch antenna is proposed for various applications, including the Global System for Mobile communication (GSM), Wireless Local Area Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX), and C-band X-band applications. The rectangular patch includes a plus-shaped slot, with an L-shaped slot cut along it, providing enhanced bandwidth and gain with multiband resonance. The radiation pattern of the proposed antenna is also better. The proposed antenna is capable of operating in four bands: (2.0 – 2.5 GHz)/2.2 GHz for GSM and WLAN applications, (3.6 – 3.9 GHz)/3.7 GHz for Wireless Fidelity (WiFi) and WiMAX applications, (6.7 -7.4 GHz)/7.1 GHz, and (9.1 – 10.8 GHz)/10 GHz for C- and X-band applications. The impedance bandwidth is 22.7%, 8.1%, 10%, and 17% for each respective frequency range. A parametric analysis of different dimensions, Voltage Standing Wave Ratio (VSWR), surface current distribution, and radiation pattern is presented to verify and validate the design parameters in each sections.

MUTUAL COUPLING REDUCTION IN STACKED STAR MIMO ANTENNA FOR WLAN AND ITU BAND APPLICATIONS

A two-port novel Stacked Star multiple-input multiple-output (MIMO) antenna with a physical size of 46 × 23 × 3.2 mm<sup>3</sup> is proposed. The proposed MIMO is designed for wireless communication applications such as Wireless Local Area Network (WLAN) and International Telecommunication Union (ITU) band resonating at 5.4 and 8.5 GHz, respectively. The Star is designed by using a basic circular antenna, from which Star geometry is constructed with iterations to obtain the desired frequency bands using Rogers RT5880 with a thickness of 1.6 mm for Stacked Star. The Stacked Star structure allows a wide bandwidth at the desired frequencies of 5.2-5.5 GHz and 8.2-8.6 GHz, respectively. To minimize mutual coupling, a T-slot stub is placed between the radiating patches. The proposed structures are simulated using Computer Simulation Technology. The proposed design is fed with proximity feed coupling for good impedance matching. Further, it provides an improved isolation of -8 dB. The important characteristics of the antenna such as reflection coefficients, Voltage Standing Wave Ratio, surface current distributions, and radiation patterns, are examined. In addition to that, MIMO characteristics elements like envelope correlation coefficient (ECC), and diversity gain (DG) and group delay -11.3 and -14.2 ns are investigated. The ECC is less than 0.01, while the DG is near 10 Db, indicating good MIMO performance. The anechoic measurement chamber and Schwarz ZVL vector network were used to measure the target MIMO antenna. The simulated and measured result shows a high degree of similarity so that the proposed antenna is strongly suggested for WLAN and ITU bands.

Design and characterization of frequency reconfigurable honey bee antenna for cognitive radio application

<span lang="EN-US">In this article, a frequency reconfigurable honey-bee compact microstrip monopole antenna is proposed which is fed by a microstrip line (50 Ω) having the capability of providing dual-band as well as triple-band operation in eight distinct modes. By embedding three PIN diodes overs the honey bee arms, the effective current distribution is controlled hence resonant frequency is also changed in eight distinct modes in real-time. This is the reason the proposed antenna is portrayed as a frequency reconfigurable antenna in this paper which is suitable for cognitive radio application. This proposed antenna can be used for various wireless application such as Bluetooth, Wi-Fi, worldwide interoperability for microwave access (WiMAX), wireless local area network (WLAN), C-band, and X-band applications. The proposed antenna possesses a planner geometry of 39×34×0.87 mm<sup>3</sup> which is printed on a substrate as flexible FR-4 (lossy) (ε<sub>r</sub>=4.4 and tanδ=0.019). The proposed antenna exhibits voltage standing wave ratio (VSWR)<2 for all 19 resonant frequencies of interest and perceptible radiation pattern over entire frequency bands with a positive gain. CST microwave studio is used to find out all simulated results of antenna parameters.</span>

A Compact-Size and High-Efficiency Cage Antenna for 2.4-GHz WLAN Access Points

In this communication, a compact-size and high-efficiency air cavity antenna with a cage-like structure is proposed for 2.4 GHz wireless local area networks (WLAN). The air cavity antenna is constructed with four sides of hybrid metallized vias, including sparsely arranged blind vias and tightly arranged shorting vias. First, the antenna size is significantly reduced by utilizing the shorting vias, which makes the antenna operate at the high-order TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\mathrm {1/2,1/2}}$ </tex-math></inline-formula> mode. Then, by loading the capacitive blind vias at the radiating apertures, the antenna size is further miniaturized. Notably, high radiation efficiency is obtained attributed to the lower dielectric loss of the air-medium structure. Finally, a prototype of the proposed cage antenna has been fabricated and tested with good agreement between simulated and measured results. In such a compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.128\lambda _{0} \times 0.128 \lambda _{0} \times 0.10 \lambda _{0}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> is the free-space wavelength at the center frequency), the measured total efficiency over 90% is achieved in the WLAN band by the cage structure. Compared with the existing 2.4 GHz antennas, the proposed one is with the ascendency of compact size and high radiating efficiency for WLAN applications.

Printed collinear dipole array antenna with a horizontally omnidirectional pattern for dual‐band WLAN

AbstractA dual‐band printed dipole array antenna for a wireless local area network (WLAN) application is presented. A radiation element consists of four pairs of printed dipoles, and two radiation elements are collinearly arrayed. A broadside coupling microstrip line‐based two‐sectional impedance transformer is used to feed the radiation elements in parallel. The proposed dual‐band antenna is designed to cover the dual‐frequency bands (2.4–2.48 and 5.15–5.825 GHz) which are the lower‐ and upper‐frequency bands for WLAN operation. The experimental results support the proposed design theory and also exhibit the gain values of 3.89–4.88 and 5.79–7.18 dBi at the lower‐ and upper‐bands, respectively, maintaining the omnidirectional radiation pattern. The measured radiation efficiencies at each frequency points, 2.4, 5.2, and 5.5 GHz are 87.39%, 75.43%, 69.96%, and 73.07, respectively. In addition, for mass production, the effect from a low‐cost flexible coaxial cable, and polyethylene housing on the antenna performance is also investigated in this letter.

Gain and bandwidth enhancement of slotted microstrip antenna using metallic nanofilms for WLAN applications

Structural modifications on microstrip patch antenna design for performance enhancement offer improvements and advantages only up to a certain limit. However, with the use of novel material in the patch area, the performance of a microstrip patch antenna can further be enhanced in terms of gain and bandwidth. In this paper, a nanomaterial-based slotted rectangular microstrip patch antenna is proposed for gain and bandwidth enhancement in Wireless Local Area Network (WLAN) applications. A conventional copper rectangular microstrip antenna (MSA) with a rectangular slot in the patch area is first fabricated and then nanomaterial is deposited in the slot area. Two types of metallic nanoparticulate thin films are deposited using Gold Nanoparticles (Au NPs) and a combination of alternate Silver-Gold-Silver Nanoparticles (Ag-Au-Ag NPs) in the slot area and the antenna parameters analyzed. A comparison between the conventional slotted MSA, and the fabricated antenna with the two different nanoparticulate thin films is presented. It is found that the Au NPs based antenna shows a 12.5 % improvement in bandwidth for a return loss of −31 dB and a 0.5 dB enhancement in gain with a nanomaterial film thickness of 264 nm. The composite Ag-Au-Ag NPs based antenna shows even better performance than the former one with an 18.75 % improvement in bandwidth for a return loss of −30 dB along with gain enhancement of 2 dB with a nanomaterial film thickness of 330 nm. Both the Au NPs and Ag-Au-Ag NPs based antennas are found to resonate at 5.89 GHz and 5.81 GHz showing an electrical size reduction of 32.09 % and 31.15 %, respectively compared to the conventional rectangular MSA.

Bandwidth enhanced deltoid leaf fractal antenna for 5.8 GHz WLAN applications

A wideband deltoid leaf fractal antenna is proposed for 5.8 GHz commonly used in industrial scientific and medical (ISM) and wireless local area networks (WLAN) applications. A microstrip patch antennas is designed with leaf shape radiating element. Using a leaf shape, it is possible to increase the perimeter of a design and thus reduce the overall dimensions of the antenna. A circular ring slot is made on the leaf shaped radiator, in a way that a circular disc is loaded at centre. Triangular fractal slots are made inside the circular disc to make it miniaturized. A partial ground is maintained with slot at centre. The antenna is fed by micro-strip feed. The locality and measurements of the fractal slots are varied to make the antenna radiate at 5.8 GHz with wider bandwidth (BW) of (2.26 GHz). The complete size of the antenna is 40 mm 3 × 40 mm 3 × 1.6 mm 3 . The step-by-step implementation of the antenna and the effects of its dimensions are compared and presented using the reflection coefficient curve. The measured reflections coefficient |S11|&lt;-10 dB maintained the operational band from (5.36 GHz - 7.62 GHz), with gain 4.2 dBi. The proposed antenna is planned and simulated using high frequency structure simulator (HFSS). The simulated and measured comparison showed good agreement, the designed antenna is suitable for 5.8 GHz WLAN applications with wider bandwidth requirements.

Performance Analysis of 1x4 RMPA Array using Step Cut and DGS Techniques with Different Feed Techniques for LTE, Wi-Fi, WLAN and Military Communications

This paper presents four different models of 1x4 antenna arrays excited by quarter wave transformer and mitered bend feeding techniques. These four antennae were designed and developed to examine the various radiation performance characteristics. The Ansys HFSS tool was used to simulate the four antenna models over the frequency range (1-5GHz). The simulation results were compared to identify the optimized design model. Both types of 1X4 arrays with mitered bend feed network showed better results than quarter wave transformer and were resonating at 2.4, 3.6, 4.5 and 4.7 GHz frequencies with a maximum gain of 13.118dB. The proposed antennae are suitable for Wi-Fi, Long Term Evolution (LTE), Wireless Local Area Network (WLAN) and military communication applications. The optimized four 1x4 array models were fabricated and tested using Vector Network Analyzer E507C. The measured results had good matching with the numerical values of the simulation results.

Design of Dual-Band, 4-Ports MIMO Antenna-Diplexer Based on Quarter-Mode Substrate Integrated Waveguide

Here, a compact, dual band, 4-elements multi-input and multi-output (MIMO) antenna diplexer is designed to use in wireless local area network (WLAN) applications. The antenna is accomplished in a planar profile by employing Substrate Integrated Waveguide (SIW) technology. To reduce the size of a single element by 75%, a quarter-mode substrate integrated waveguide (QMSIW) technology is introduced. The QMSIW is realized by bisecting the full-mode SIW along the two magnetic walls and considering the quarter-mode for the operation. Initially, two-QMSIW cavities of distinct dimensions are designed to operate in two frequency bands, 5.2 GHz and 5.8 GHz, respectively. Later, two more radiating elements operating at the same frequencies are integrated with a 2-elements antenna. For better polarization decoupling, the identical elements are placed perpendicular to each other, and a parasitic metallic strip loaded with shorting vias is placed between two identical frequency antenna elements; hence, the port isolation is improved up to −25 dB. The antenna covers a bandwidth of 1.8% in the lower frequency band while 2.2% in the upper frequency band. The antenna prototype is fabricated, and its results are verified with experimental data. It is observed that the measured results are closely following the simulated results.

Reference-Modulated PI-DCSK: A New Efficient Chaotic Permutation Index Modulation Scheme

In this paper, we propose a reference-modulated permutation index differential chaos shift keying (RM-PI-DCSK) over multipath fading channels. Due to quasi-orthogonal property between different permutated chaotic signals, the proposed scheme can remarkably suppress the inter-sequence interference to recover the desired information. Moreover, the proposed RM-PI-DCSK has one more modulation bit in the reference segment than the conventional permutation index differential chaos shift keying (PI-DCSK). Both the reference signal in the first time-slot and a permuted replica of the reference in the second time-slot are modulated for efficient transmission. The theoretical bit-error-rate (BER) performance and the highly consistent simulation results demonstrate that the proposed RM-PI-DCSK can achieve a performance gain 3 dB over the conventional PI-DCSK at a BER of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$10^{-4}$</tex-math></inline-formula> , and this gain becomes larger in a high-delay-spread channel. In particular, the performance superiority of the RM-PI-DCSK is further demonstrated in a typical ultra-wideband (UWB) channel with narrow-band interference. Therefore, this proposed scheme can be deemed as an efficient transmission alternative for chaotic-based wireless communications, such as in wireless local area network (WLAN) applications and indoor applications of the transmitted-reference UWB.

Low Profile Monopole Meander Line Antenna for WLAN Applications.

An antenna assumes a significant role in expanding the levels of communication to meet the demands of contemporary technologically based industry and private data services. In this paper, a printed compact meander line patch antenna array for wireless local-area network (WLAN) applications in the frequency span of 2.3685–2.4643 GHz is presented. The impedance matching of the antenna is generated by applying a partial rectangular-shaped ground plane backside of the meander line antenna. The proposed antenna evolved on the Rogers RT5880 substrate with a dielectric permittivity of 2.2, and the height of the substrate was 1.575 mm to accomplish the lowest possible return loss. The proposed antenna was developed to achieve particular outcomes, for example, voltage standing wave ratio (VSWR) 1.32, reflection coefficient 20 dB with a bandwidth of 94.2 MHz, a gain of 2.8 dBi, and an efficacy measurement of 97%. This antenna is appropriate for WLAN applications that utilize a 2.4 GHz resonance frequency. The overall dimensions of the antenna are 15 mm × 90.86 mm.

The Design of a Superstate NZIM-Antenna Array for WLAN Application

With the development of telecommunications and its applications, the design of compact antennas with high performance has become a great necessity. Among the important requirements is a high gain. In this article, a microstrip patch antenna using near zero-index metamaterial (NZIM) is proposed. This prototype is designed with the designing parameters of a rectangular microstrip patch antenna. The substrate material is FR-4. Simulation results show that this antenna operates at 5.8 GHz for a wireless local area network (WLAN). The proposed single antenna element achieves side-lobe suppression better than -13 dB. The 4×4 proposed antenna array is designed using 16 single elements and a T-shaped power divider to split power for each element. By covering a single-layer NZIM coating with a 4×4 array over a microstrip antenna, a gain enhancement of 14 dB is achieved in comparison with the single element. Over the operating band, the antenna prototype demonstrates steady radiation patterns. These characteristics are in good agreement with the simulations, rendering the antenna a good candidate for 5G applications. These antennas are designed, optimized, and simulated using CSTMWS2020.

Frequency reconfigurable circular microstrip patch antenna with slots for cognitive radio

In this paper, a novel multi-frequency microstrip antenna with complementary ring slot resonator (CRSR) structure that satisfies Bluetooth, worldwide interoperability for microwave access (WiMAX), and wireless local area network (WLAN) applications is proposed. The conventional antenna consists of a circular microstrip patch at a resonance frequency band of 2.5 GHz. By loading two CRSR at the radiating element, three operating frequency bands 2.5 GHz, 3.6 GHz, and 5.2 GHz are achieved. The operational bands covered by the antenna are Bluetooth 2.5 GHz, WiMAX 3.6 GHz, and WLAN 5.2 GHz. The insertion of CRSR to patch antenna has made it possible to compact and simple design, and miniaturized antenna for cognitive radio. Moreover, the directivity of the proposed antenna is adequate with acceptable radiation properties and perfectly matches with the simulated and measured results.

A Wrench-Shaped UWB Antenna Yielding Dual Notched Bands for WLAN Application

A wrench-shaped ultrawideband (UWB) antenna with dual notched bands is proposed and investigated. The antenna has a wrench-shaped patch and two T-shaped slots on the ground, realizing the required UWB band. To achieve the dual notched band characteristics in upper and lower wireless local area network (WLAN) bands, an Omega-shaped slot is etched on the feedline and a novel composite right/left-handed electromagnetic bandgap (CRLH-EBG) structure is built on the ground. Measured results present an operating frequency band from 3.04 to 11.4 GHz, with two notched bands of 5.1–5.4 GHz (uplink of WLAN band) and 5.7−5.985.7-5.98 GHz (downlink of WLAN band), respectively. Both measured and simulated results of the proposed antenna are exhibited, promising that the antenna applies to UWB applications and can precisely overcome WLAN interference.

Ultra-Compact Slitted Flower-Shaped Dual-Band Monopole Antenna for Modern Portable Devices

A meanderingly slitted bio-inspired (MSB)-shaped antenna is presented in this work. The footprint of the proposed MSB antenna is 12 × 10 mm2 0.12 × 0.10 λ g 2 at 2.1 G H z . The MSB antenna proposed in this operates at 2.1 GHz and 5.2 GHz frequencies with a bandwidth of 70 MHz and 570 MHz and a radiation efficiency of 52.5% and 96%, respectively, which is suitable for UMTS, radio navigation, Long Term Evolution (LTE), and 5 GHz Wireless Local Area Network (WLAN) applications. The proposed MSB antenna demonstrates a peak gain of 2.9 dBi at 5.2 GHz and an omnidirectional radiation pattern at both E-plane and H-plane in both operating bands. The fabrication and measurement of the proposed antenna prototype are presented. The parametric study of the proposed structure is performed and presented. Therefore, the proposed antenna is a promising candidate for modern portable devices.

Design of Decimation Filters for Wireless Local Area Network Applications

Multirate signal processing is critical to realizing the digital frequency converter in WLAN technologies. In this paper, we focus on designing and analyzing the different structures of decimators that support WLAN-b applications to reduce the frequency by 12 for an IEEE. The structure modeling of the decimator used Simulink. Implementing a single-stage decimator required a higher-order filter, extra storage space, and a long simulation time. Results showed that the necessary storage elements for 2-stage design are 55% and for 3-stage design is 65% of single stage. For 133 MHz WLAN-b application, a two-stage decimator is proved to be efficient.

A fully integrated GaAs HBT power amplifier with enhanced efficiency for 5-GHz WLAN applications

An efficiency-enhanced fully integrated power amplifier (PA) for wireless local area networks (WLANs) was implemented based on the GaAs heterojunction bipolar transistor (HBT) process. A harmonic tuning network that can absorb the parasitic inductance of the bonding wires is proposed, which reduces the chip area significantly. The network provides nearly optimum fundamental and second harmonic impedances from 5.0 to 5.5 GHz. Additionally, a novel adaptive bias circuit that corrects the AM-AM and AM-PM distortion and improve thermal stability at high input power was proposed. With a chip dimension of only 1.06 mm2, the PA achieves a gain of 31.1-31.6 dB and saturated power of 29.9-30.3 dBm with a peak power-added efficiency (PAE) of 49.3%-51.8% across 5.0-5.5 GHz. The PA also shows an output power of 22.1 dBm (EVM=-32 dB) with 18.4% PAE under an 802.11ac MCS9 VHT160 test signal. In addition, the PA delivers 17.5 dBm (EVM=-42 dB) output power when tested with the 802.11ax MCS11 VHT160 signal at 5.25 GHz.

A compact four-band high-isolation quad-port MIMO antenna for 5G and WLAN applications

A miniaturized quad-port multiple-input-multiple-output (MIMO) antenna, generating four-band and high port isolation properties, is developed for 5G and wireless local area network (WLAN) applications. The realized MIMO antenna consists of four elements. Each element combines multiple L-shaped and rectangular branches with concave grounds, so that good impedance matching in four frequency bands is reached. The four elements are orthogonally placed to reduce current coupling. Moreover, four pairs of rotationally symmetrical strip lines are added to further improve the isolation between the units at low frequency. The antenna has been optimized to achieve a compact size of 39 mm × 39 mm × 1.6 mm, covering three 5G bands (2.6/3.5/4.8 GHz) and the 5.8 GHz WLAN band. In addition, inter-port isolation is better than 21.5 dB. Furthermore, the measured envelop correlation coefficient is smaller than 0.012 in the desired bands. Measurements also show that the radiation patterns and gains of the fabricated antenna agree well with the simulated ones. The diversity gain is as good as 9.94 dB. Moreover, the channel capacity loss is satisfactory, being below 0.4 bits/s/Hz. Satisfactory efficiency and diversity performance are realized. These facts indicate that the antenna system is a promising candidate for MIMO usage on 5G and WLAN devices.

A New Compact Dual-Polarized MIMO Antenna Using Slot and Parasitic Element Decoupling for 5G and WLAN Applications

This paper presents a compact dual-polarized multiple-input multiple-output (MIMO) antenna for fifth generation (5G) and wireless local area network (WLAN) applications. At first, a compact two-element dual-polarized MIMO antenna designed to operate at 3.5 GHz was developed. After that, some modifications were performed in the initial configuration, and a compact two-element dual-polarized MIMO was designed to operate at 3.5 and 5.35 GHz. A simple decoupling technique using parasitic element and slot was used to enhance the isolation between the radiating elements and to achieve an isolation above 18 dB over the band ranging from 3.4 to 3.6 GHz for the first antenna, and to achieve isolations above 19.8 dB over the first band ranging from 3.4 to 3.6 GHz and above 16.75 dB over the second band ranging from 5.15 to 5.85 GHz for the second antenna. Simulations were performed in the Ansoft HFSS software for numerical characterization and the prototype was fabricated with FR-4 dielectric and measured, presenting a good agreement between simulated and measured results. Furthermore, the envelope correlation coefficient (ECC) and the diversity gain (DG) were analyzed and present good results.