Wireless Local Area Network Applications Research Articles

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.

Characteristic mode analysis of two port semi‐circular arc‐shaped multiple‐input‐multiple‐output antenna with high isolation for 5G sub‐6 GHz and wireless local area network applications

SummaryThe work presents the design of a novel semi‐circular arc‐shaped two‐element multiple‐input‐multiple‐output (MIMO) antenna with improved isolation. The antenna is obtained by cutting and subtracting a circular disk from another circular disk, forming the shape of a semi‐circular arc. The antenna is replicated to form a two element MIMO antenna system on a FR4 substrate of size 36 × 26 mm2 with edge‐to‐edge separation of 12.4 mm. The developed MIMO antenna resonates in the frequency range 3.26 to 6.97 GHz giving a maximum element‐to‐element isolation around 26 dB in the operating bandwidth. Also, the antenna gives a maximum radiation efficiency of 98% with a peak gain of 5.3 dBi in the operating band. The proposed compact MMO antenna covers wide variety of wireless applications like 5G sub‐6 GHz and wireless local area network (WLAN) applications, which includes n77/n78/n79, WiFi‐5, V2X/DSRC, WiFi‐6, and INSAT‐C bands. Characteristic mode analysis (CMA) is performed in characterizing the performance of the antenna over the specified operating bands by studying and analyzing the parameters like modal significance (MS), characteristic angle (CA), modal current, and modal patterns. The obtained MIMO parameters like envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), and total active reflection coefficient (TARC) reveal that the proposed antenna is a suitable choice in MIMO environment.

A multimode substrate integrated waveguide based s elf‐hexplexing antenna for mobile terminal applications

A low-profile self-hexplexing antenna based on the multimode substrate integrated waveguide (SIW) cavity is presented for mobile terminal applications. It has three feeding ports, each of which can generate two resonant modes. Taking the advantage of the truncated SIW resonant cavity, the footprint of the antenna remains compact in the multiple functional mode scenario. The proposed antenna operates at six different modes, namely TM10 mode at 3.55 GHz, TM01 mode at 4.85 GHz, TE110 mode at 2.45 GHz, TE220 mode at 5.6 GHz, TE110 mode at 3.4 GHz and TE120 mode at 5.35 GHz. Good agreement is achieved between the simulated and measured antenna performance. The excitation and field distribution of each mode is analyzed. Keeping the structure miniaturized, the proposed antenna realizes hex-band characteristics without excessive feeding ports. It can be used for Microwave Access (WIMAX), the 5th Generation Mobile Communication Technology (5G) and Wireless Local Area Network (WLAN) applications, which is suitable for mobile handheld multiband terminals.

Highly efficient microstrip patch antenna for wireless gigabit alliance applications

A <span>wireless gigabit alliance (WiGig) is widely known for higher bandwidth which operates at 60GHz unlicensed spectrum for super-fast data speed over short distances for millimeter-wave band application. This study offers an efficient, compact microstrip patch antenna for WiGig with a lesser return loss -50.45 dB (60 GHz). The gain and directivity of the proposed antenna are 13.01 dB and 13.42 dBi. It provides higher efficiency of around 91%. The proposed antenna also covers another mm-wave band that is at 95 GHz. The U.S. military uses electromagnetic radiation of 95 GHz as a non-lethal weapon. So, the anticipated antenna can be used for a miniaturized active denial system. The proposed antenna has a good gain, directivity, and efficiency for the multigigabits/s data rate. The aforesaid properties imply that it can be used for wireless personal area networks (WPAN) and wireless local area network (WLAN) and fifth-generation (5G) applications too.</span>

Isolation enhancement in dual-band MIMO antenna by using metamaterial and slot structures for WLAN applications

A dual-band multiple-input multiple-output (MIMO) antenna with enhanced isolation operating in 2.35–2.50 GHz and 5.13–5.88 GHz bands is investigated and presented. The proposed antenna system is deformed from two inverted-F antennas, and the distance between the antenna elements is only 0.104 (—wavelength of 2.4 GHz). To enhance isolation and reduce mutual coupling, the metamaterial and slot structures are efficiently and innovatively designed on the ground plane for two bands. Both decoupling methods effectively improve the antenna isolation, with metamaterials acting on the lower band and slots acting on the higher band. The mutual coupling at 2.4 GHz and 5.5 GHz is reduced by 15.24 dB and 8.19 dB, respectively. Then, the optimized MIMO antenna can cover both 2.4 GHz and 5 GHz wireless local area network (WLAN) bands, and has the advantages of wideband, compact size, good radiation, enhanced isolation, and low envelope correlation coefficient. The measured results agree with the simulated results, which shows that the proposed MIMO antenna system has potential application value in WLAN system.

A Compact Dual-Band Bandpass Filter Using Coupled Microstrip Lines

In this paper, a new compact dual-band bandpass filter (DB-BPF) is proposed using parallel coupled lines. The design method is based on introducing transmission zeros (TZs) in the frequency response of a single-wideband filter. In the proposed structure, three coupled lines and a multi-mode resonator are used to realize the wide bandpass filter. Meanwhile, two coupled lines that are connected at the end and loaded by an open-circuit stub are employed to make a new notch filter. The proposed DB-BPF is designed and fabricated on Rogers RO3210 substrate for Wireless Local Area Networks (WLANs) applications. The simulation results show good agreement with measurements. The measured results exhibit two passbands centered at 2.4 and 5.2 GHz, having an insertion loss of less than 0.1 dB and 0.9 dB, respectively. Low insertion loss, compact size, and high attenuation between two passbands are the main advantages of the proposed DB-BPF.

Multiband Planar Antenna for Long Term Evaluation and Wireless Local Area Network Applications

In this paper, a planar antenna for Long Term Evolution (LTE) bands and Wireless Local Area Network (WLAN) is proposed. The antenna is based on a coupled-fed monopole with a distributed inductor and a direct-fed monopole. These three components form two bands of operations namely a low operating band from 0.59 to 0.635 GHz and a high operating band from 1.67 to 2.80 GHz. The two operating bands satisfy the WMTS 610, UMTS 1700, GSM 1800, LTE 1900, LTE 2100, WLAN 2400, LTE 2600 and WLAN 3600 applications. The proposed antenna having dimensions 75 × 10 × 0.8 mm3 is suitable for the top edge of a mobile handset and a copper plate of 75 × 100 mm2 (5 inches screen plate), is used as the ground plane system.

A MIMO Antenna with High Gain and Enhanced Isolation for WLAN Applications

In this paper, a novel two-port dual-band multiple-input-multiple-output (MIMO) antenna with enhanced isolation and high gain is presented. The presented antenna is composed of a symmetrical ground element and two identical antenna radiating elements. At the bottom of the substrate, the ground part is applied to strengthen the isolation performance of the designed MIMO antenna. The measured −10 dB bandwidth according to the input reflection coefficient S11 are 650 MHz (2.25–2.9 GHz) and 980 MHz (5.05–6.03 GHz), which are in strong agreement with the 2.4 GHz frequency band (2.4–2.4835 GHz) and the 5 GHz frequency band (5.15–5.85 GHz) of wireless local area network (WLAN) applications. The measured S21 at both the lower and the higher frequency operation bands are less than −19.3 dB. In the operating frequency bands, the measured gain is from 1.5 dBi to 3.8 dBi. The measured results show that the presented MIMO antenna is a good candidate for WLAN applications.

Investigation on Performance of Microstrip Patch Antenna for a Practical Wireless Local Area Network (WLAN) Application

Abstract: The performance of a microstrip patch antenna for a practical wireless local area network application is investigated in this research. This design is built around the transmission line concept. The antenna design substrate is FR4 (lossy) with a dielectric constant (Er) of 4.3 dielectric material, and the ground and patch materials are copper (annealed). The substrate is 71.62mm in width and 55.47mm in length. The height of the dielectric material is 1.6mm, which is the normal size for FR4 material. The conducting patch element has a width of 35.81mm and a length of 27.73mm for a resonance frequency of 2.573 GHz. A simulation with CST studio suite was used to optimise the antenna design. Keywords: Microstrio patch antenna, CST suite, WLAN application, Transmission line, Antenna design

Compact Broadband Antenna with Vicsek Fractal Slots for WLAN and WiMAX Applications

This paper aims to design a compact broadband antenna for wireless local area network (WLAN) and worldwide interoperability for microwave access (WIMAX) applications. The suggested antenna consists of an octagonal radiator with Vicsek fractal slots and a partial ground plane, it is printed on FR-4 dielectric substrate, and its global dimension is 50 × 50 × 1.6 mm3. The antenna is designed and constructed using both CST MICROWAVE STUDIO® and CADFEKO electromagnetic solver, and in order to validate the acquired simulation results, the antenna is manufactured and tested using vector network analyzer E5071C. The measurement results show that the designed antenna attains a broadband bandwidth (S11 < −10 dB) from 2.48 to 6.7 GHz resonating at 3.6 and 5.3 GHz, respectively. The broadband bandwidth covers the two required bands: WiMAX at the frequencies 2.3/2.5/3.3/3.5/5/5.5 GHz and WLAN at the frequencies 3.6/2.4–2.5/4.9–5.9 GHz. In addition, the suggested antenna provides good gains of 2.78 dBi and 5.32 dBi, omnidirectional measured radiation patterns in the E-plane and the H-plane and high efficiencies of 88.5% and 84.6% at the resonant frequencies. A close agreement of about 90% between simulation and measurement results is noticed.

Designed Circularly Polarized Two-Port Microstrip MIMO Antenna for WLAN Applications

The proposed work describes a corner square-cut square-patch multiple-input multiple-output (MIMO) antenna with reduced mutual coupling for circular polarization (CP). A two-port MIMO-CP antenna was designed and operated at 5.6 GHz for wireless local area network (WLAN) applications. The dimensions of the MIMO-CP antenna were 22.5×50mm2(0.43λ0×0.933λ0) and the FR4 substrate height was 1.6 mm. Between the two-elements, the edge-to-edge distance was 12.2 mm (0.227 λ0), where λ0 was the free space wavelength at 5.6 GHz. A slot was created in the middle of the ground in the proposed MIMO antenna to reduce mutual coupling and improve CP. The ground slot improves impedance matching and provides a better S-parameter and axial ratio (AR), according to the antenna results. According to the simulated results, the proposed antenna bandwidth of 5.23–6.42 GHz (21.4%) for S11 were <−10 dB, isolation was −37 dB with a peak gain of 6 dB and AR ≤3 dB from 5.37 to 5.72 GHz (6.25%). The proposed antennas are simple to fabricate, have low profiles, are inexpensive, have good isolation, and are CP. The diversity gain (DG) and envelop correlation coefficient (ECC) results are better in the simulated frequency band. A MIMO-CP antenna geometry prototype is built and measured for comparison, yielding good results when compared to the simulated and measured results. The MIMO-CP antenna, as designed, is suitable for WLAN applications.

Dual-Band Circularly Polarized Omni-Directional Biconical Antenna With Double-Circular Parallelepiped Elements for WLAN Applications

This research proposes a novel dual-band (2.45/5.80 GHz) omnidirectional circularly polarized (CP) biconical antenna with double-circular parasitic parallelepiped elements for wireless local area network (WLAN) applications. The proposed dual-band CP antenna scheme consisted of a biconical radiating structure surrounded by inner- and outer-circular parallelepiped elements that convert linearly polarized electric fields into CP fields. Simulations were performed to optimize the antenna parameters, and an antenna prototype was fabricated and experiments were conducted. The measured impedance bandwidths (IBWs) were 44.4% (1.84 – 2.89 GHz) and 4.56% (5.73 – 5.99 GHz) for the lower- (2.4 GHz) and upper-frequency (5.80 GHz) bands, respectively. The corresponding 3-dB axial ratio bandwidths (ARBWs) were 11.22% (2.27 – 2.54 GHz) and 10.49% (5.6 – 6.2 GHz). The radiation patterns of the dual-band antenna scheme were omnidirectional left-hand circular polarization, with the measured antenna gains of 3.2 dBic and 8.5 dBic at 2.45 and 5.80 GHz, respectively. The simulated and measured results were reasonably agreeable. Despite the narrow IBW and ARBW for the upper-frequency band, the bandwidths adequately covered the target upper frequency band, rendering the proposed CP omnidirectional biconical antenna scheme operationally suitable for WLAN applications. Furthermore, the novelty of this research lies in the use of a biconical radiating structure augmented with double-circular parasitic parallelepiped elements to realize circular polarization for dual-band WLAN applications.

A CPW-Fed Circular SRR-Inspired Flexible Antenna Using Polydimethylsiloxane (PDMS) Substrate for WLAN and WBAN Applications

This article presents a <inline-formula> <tex-math notation="LaTeX">$50\times40$ </tex-math></inline-formula> mm² coplanar waveguide (CPW)-fed triple-band flexible antenna operating at 5, 5.8, and 6.6 GHz for wireless local area network (WLAN) and wireless body area network (WBAN) applications. In the proposed design, polydimethylsiloxane (PDMS) is used as a substrate with a dielectric constant <inline-formula> <tex-math notation="LaTeX">$\varepsilon _{r}$ </tex-math></inline-formula> of 2.65 and a loss tangent tan<inline-formula> <tex-math notation="LaTeX">$\delta _{\varepsilon r}$ </tex-math></inline-formula> of 0.02. In addition to the rectangular slot on the ground, the presented antenna has a single circular split-ring resonator (SRR) structure on the same side of the patch. This provides the required frequency notched characteristics for the targeted frequency bands, compactness, minimize losses, and backward radiation when used in close proximity to the human body. The proposed flexible antenna provides stable results in terms of performance parameters and specific absorption rate (SAR). We have also investigated the antenna under different operating conditions of moisture and bending. There exists a strong correlation between the simulation and measured findings.

Asymmetric microstrip fed meander line slot antenna for 5.6 GHz applications

This paper presents the design of a meander line slot antenna. The designed antenna operates at the frequency range of 5.45 GHz to 5.7 GHz covering wireless local area network applications. The proposed antenna comprises a circular patch design with a meander slot embedded within the patch. Besides to meander line slot structure, asymmetric microstrip feed is provided to the antenna. To achieve better antenna performance, parametric studies are carried out. The antenna's total size is 15 × 14 × 1.57 mm3. For the designed antenna, the −10 dB impedance bandwidth is 4.48 %, the gain is 1.3 dBi with a radiation efficiency of 84.43 %. The current distribution and radiation pattern of the proposed meander slot antenna have been observed and simulated.

Four Elements Reconfigurable MIMO Antenna for Dual Band Applications

Four-element reconfigurable multiple-input-multiple-output (MIMO) antennas for dual band applications are proposed. The frequency reconfigurability of the proposed antennas is achieved by incorporation of three PIN diodes within the single element. The antenna covers multiple switchable operating bands for Worldwide Interoperability for Microwave Access (Wi-MAX)/Wireless Local Area Network (WLAN) applications (3.4-3.6GHz, 3.8-3.86GHz, 5.18-5.27GHz, 5.35-5.5GHz and 5.67-5.8GHz). The proposed MIMO antenna consists of 2x2 elements on a single FR4 substrate.The combinations of MIMO and reconfigurable antenna provide improved performance in terms of envelope correlation coefficient (ECC) and channel capacity loss (CCL) in multiple-frequency bands. The MIMO antenna system performance including the isolation, ECC, CCL, and the diversity gain (DG) are simulated and measured. High isolation (≥ 25dB) is achieved between reconfigurable MIMO antenna ports without any internal and external decoupling network. The proposed antenna has sufficient performance that makes it suitable for indoor access points (IAPs).

A Compact Quad-Band Sickle-Shaped Monopole Antenna for燝SM�00/WiMax/WLAN Applications

In this paper a novel, compact, microstrip-fed, quad-band monopole antenna is presented for the application of Global System for Mobile communication (GSM 900), Worldwide Interoperability for Microwave Access (WiMAX) and Wireless Local Area Network (WLAN). The proposed antenna comprises of a sickle-shaped structure with four circular arc strips, and a modified rectangular ground plane. The four strips of the antenna are independently responsible for the four different resonant frequencies of the operating bands and can be tuned separately to control the radiation performance. The proposed quad-band antenna is designed to resonate at 940 MHz for GSM 900, 2.5 and 3.5 GHz for WiMAX and 5.85 GHz for WLAN applications. At the four intended operating bands, the antenna exhibits impedance bandwidth of 60 MHz (905–965 MHz), 80 MHz (2.45–2.53 GHz), 110 MHz (3.48–3.59 GHz) and 2.39 GHz (4.82–7.21 GHz), respectively. At the resonance frequency of the four bands, the gain of the proposed antenna is obtained as 4.2, 2.5, 1.7 and 1.9 dBi, respectively. A prototype of the designed antenna is fabricated and a good agreement between simulated and measured results is observed. Furthermore, the proposed antenna shows good radiation characteristics and gains at all the four operating bands.

High Isolated MIMO Antenna for WLAN Applications

This paper presents a compact multiple-inputs multiple-outputs (MIMO) antenna for wireless local area network (WLAN) applications. The proposed four-port MIMO antenna has been incorporated with its four identical elements having dimensions of 10[Formula: see text]mm [Formula: see text] 12[Formula: see text]mm each. The MIMO antenna is designed to operate in the range of 5.17–6.25[Formula: see text]GHz frequency band having impedance bandwidth of 18.91%. The antenna is fabricated on a glass epoxy FR-4 substrate having a thickness of 0.8[Formula: see text]mm for measurement and validation. The measured results show that the antenna has good isolation greater than [Formula: see text]17[Formula: see text]dB to [Formula: see text]25[Formula: see text]dB, better impedance matching and envelope correlation coefficient (ECC) below 0.03 over the entire band of operation. The proposed MIMO antenna is a potential candidate for WLAN applications.

A substrate integrated suspended line gain‐enhanced patch antenna with high‐order mode suppression by feeding structure design using characteristic mode analysis

AbstractA substrate integrated suspended line (SISL) gain‐enhanced patch antenna is proposed. Enhanced gain is obtained by a long patch. To suppress the high‐order mode in the anticipated band, a feeding structure is designed with the assistance of characteristic mode analysis. The proposed SISL antenna with the proposed feeding structure suppresses higher‐order modes, achieves good impedance matching and stable broadside gain across the operating frequency band. The antenna has the potential to satisfy wireless local area network (WLAN) application. Measured results show that the 10‐dB impedance bandwidth for the proposed antenna is 18.6% from 4.93 to 5.94 GHz with an average gain of 8.34 dBi. The measured results show great agreement with simulated results.

Analysis of the Electromagnetic Absorption in a New Design of PIFA Antenna Using Metamaterials

This paper presents the design, simulation and fabrication of a miniaturized wearable dual-band antenna put on a rigid substrate and operable at 2.45/5.8 GHz for wireless local area network applications. The electrical and radiation characteristics of the developed antenna were obtained by means of the technical insertion of a slot to tune the operating frequencies. To study the impact of the electromagnetic radiation of the structure of the human body, it is necessary to minimize the back radiation towards the user. Therefore, in this work, a multi-band artificial magnetic conductor (AMC) was placed directly above a dual-band planar inverted F antenna to achieve a miniaturization with excellent radiation performance. The simulations were carried out using the computer simulation technology CST Microwave Studio (CST MWS). A good agreement was achieved between the simulation and experimental results. The comparison of the measurement findings indicates that, when the antenna was backed by the AMC plane, the gain improved from 1.84 to 3.8 dB, in the lower band, and from 2.4 to 4.1 dB in the upper band. The front-to-back ratio of the AMC backed PIFA antenna was also enhanced. Then, to ensure that the proposed AMC structure is harmless to the human body, this prototype was placed on three-layer human tissue cubic model. It was observed that, due to the inclusion of an AMC plane, the peak specific absorption rate (SAR) decreased to 1.45 and 1.1 W/kg at 2.45 and 5.8 GHz, respectively (a reduction of around 3.7 W/kg, compared with an antenna without (AMC).

Ram Horn-Shaped Inspired Folded Compact Antenna for 4G LTE-A and WLAN Portable Mobile Applications

A compact dual-band ram horn-like folded antenna is presented in this work. The antenna is based on a ram horn-like folded strip, asymmetric microstrip feeding (AMF) technique, partial ground, and protruding stub at the ground plane. The dimension of the proposed antenna is 0.11 λ g × 0.17 λ g at 2.3 GHz (10 × 15 mm2). The proposed shape is achieved through the combination of two circular arcs with different radii. The antenna operates at 2.3 GHz and 5.8 GHz with a measured bandwidth of 100 MHz and 820 MHz, a gain of 0.62 dBi and 2.2 dBi, and radiation efficiency of 93.67% and 99.87%, respectively. The prototype of the proposed antenna is fabricated and measured. The measured result shows a good agreement with the simulated result. The parametric study of the proposed antenna is performed and results are presented. Besides, a comparative study between the antennas proposed in this work and the state of the art is performed and presented. The proposed antenna is comparatively small in size than all the recently reported works in the literature while ensuring good radiation characteristics. Therefore, the antenna proposed in this work is a better candidate for future portable sub-6GHz fifth-generation (5G), Advance Long-term Evolution (LTE-A), Worldwide Interoperability for Microwave Access (WiMAX), and Wireless Local Area Network (WLAN) applications.