WiMAX Applications Research Articles

Octagonal Microstrip Patch antenna array with gain enhancement for WiMAX and WLAN Applications

An octagonal microstrip patch antenna is presented in this paper. A small sized microstrip patch antenna with a high gain has been the focusing point of so many researches over the years. Microstrip patch antenna is basically known to have a low gain as a result various techniques are carried out in order to enhance the gain. In this work, a single patch octagonal microstrip patch antenna and a 1x2 octagonal patch antenna array are designed and the effects are studied. The structure is designed on four different substrates FR4, Duroid, Arlon and Rogers substrate materials. Copper is used as the patch and ground material. The antenna is designed on a small substrate material and it is probe fed. The simulated results of the array reveals a gain increase of 6.25dB from 3.6dB of the single patch on the FR4 substrate. The simulated results of the antenna in terms of reflection coefficients, voltage standing wave ratio (VSWR) and gains realized showed that the antenna has prospective applications for 4.6 and 5.9GHz applications. Conclusively, the antenna with the FR4 substrate shows the best antenna performance in terms of Gain and Return loss and its operating frequency falls under the WiMAX and WLAN range compared to the other substrates. The tool used for the design and simulation is the Computer Simulation Technology (CST) microwave studio.

A Microstrip MIMO Antenna with Enhanced Isolation for WiMAX Applications

In this paper, a multiple-input multipleoutput (MIMO) antenna with high isolation is designed using defected ground structure (DGS). The proposed antenna is constructed by two sets of four elements (2×2), which are designed at the central frequency of 3.5 GHz for Worldwide Interoperability for Microwave Access (WiMAX) applications. The antenna is fabricated on a FR4 substrate with an overall size of 144 × 99 × 1.6 mm. Thanks to DGS, the designed MIMO antenna achieves a high isolation of 30 dB and a high radiation efficiency of over 90%. Besides, this MIMO antenna attains a 7.5 dBi gain. There is a good agreement between the simulated S-parameters and the measurement results.

A Dual-band Circularly-polarized Printed Monopole Antenna for Wi-Fi and WiMAX Applications

This paper presents a rectangular-shaped printed monopole antenna with circular polarization for Wi-Fi (2.4–2.484 GHz) and WiMAX (3.3-3.7 GHz) bands. The antenna relies on asymmetric arrangement of the patch with respect to the microstrip feed, in order to generate circular polarization. Dual-band (Wi-Fi and WiMAX) operation is enabled by inserting a slit in the corner of the ground plane. Simulation results show a bandwidth increase of 15.9% (2.2–2.58 GHz) for Wi-Fi, and of 24.16% (3.13–3.99 GHz) for WiMAX applications. Furthermore, beamwidths at the axial ratio of 3 dB equal 48˚ and 51˚ for the x-z plane and y-z planes, respectively.

Design and Development of a Compact Triple-Band Microstrip Patch Antenna Loaded with Shorting Pin.

A single layer coaxial probe fed compact shorted patch antenna capable of triple band operation for GSM, ISM and WiMax application has been designed, fabricated and analyzed. The designed antenna generates three separate resonances to cover 1.9 GHz DCS, Bluetooth and WLAN (2.4 GHz), 3.5 GHz WiMax bands while maintaining a small overall size of 36*28*1.6 mm3. A prototype is fabricated and experimental results show good radiation characteristics over the operating bands.

Tunable PDEBG using ferrite‐based metasurface for WiMaX application

This article presents a tunable ferrite-based anisotropic reflective metasurface, which provides a method to manipulate the TE and TM polarized waves separately, and has much stronger ability to control electromagnetic waves and provides different phase difference between two reflected polarized waves. This eventually leads to various polarized reflected waves starting from linear polarization to RHCP and LHCP. Ferrite slab is used for realizing anisotropic behavior. A novel method for tunability of single polarization response is observed. A wired dipole antenna operating at 3.5 GHz is designed above metasurface at height d. 95 k A/m of DC biasing is applied in both X and Y directions in ferrite-based metasurface to obtain RHCP and LHCP reflected waves from linearly polarized incident waves from metasurface. Moreover, polarization switchable dipole antenna is realized by changing the biasing direction. Furthermore by varying biasing, tunability of AR is realized from 3.3 to 4 GHz. The metasurface is simulated and designed on HFSS v.16.

Isolation Frequency Switchable MIMO Antenna for PCS, WIMAX and WLAN Application

In this study, a lumped component based frequency reconfigurable multiple-input-multiple-output (MIMO) receiving wire design is presented. The proposed antenna is composed of a planar structure in form of F-shaped together with a slotted and defected ground structure for bandwidth and isolation enhancement. The MIMO antenna operates in six frequencies upon the state of the four lumped element switches. The proposed receiving wire design exhibits a multiband frequency reconfigurable characteristics from 1-7GHz with isolation of more than 14dB for the whole band, with efficiency of about 75%. The MIMO antenna’s behavior in terms of ratio of square root of the sum of power reflected wave to the incident wave (TARC), ECC and CCL are all within the acceptable limits. The design is suitable for personal communication system (PCS), WIMAX and WLAN wireless applications.

Frequency reconfigurable stepped impedance dipole antenna for wireless applications

A stepped impedance (SI) based frequency tunable dipole antenna for WLAN (2.4–2.48 GHz)/Bluetooth (2.4–2.48 GHz)/LTE (2–2.7 GHz)/wireless power transfer/UMTS (2.1 GHz)/WiMAX (2.5–2.7 GHz) applications has been investigated in this paper. The proposed antenna has an overall dimension of 0.408 λ0 × 0.245 λ0 × 0.013 λ0, where λ0 represents the free-space wavelength at the frequency 2.45 GHz. By embedding varactor diodes on the SI dipole antenna arms and varying the bias voltage, the effective electrical length of the antenna can be changed, leading to an electrically tunable antenna without changing the length of the antenna. The simulation and experiments are well matched and offer a 2:1 VSWR (S11 <−10 dB) bandwidth of 780 MHz. Experimental results show that by trimming the varactor diode, the operating frequency of the antenna can be electrically tuned from 1.98 to 2.76 GHz.

Design of Feeding Techniques for Slotted Rectangular Microstrip Patch Antenna (RSMA)

Microstrip Patch Antenna is a compact low profile antenna which can be embed on the surface. This paper explains various feeding techniques applicable for rectangular microstrip antenna for 3.4 to 3.6 GHz for WiMax applications. Based on contact and non-contact techniques various feeding methods are discussed here. RF power is feed directly to the patch using conducting element for contact feed where as in non-contact feed the power is feed to the patch and the microstrip line through electromagnetic coupling. The simulation results shows the comparative study of various performance metrics such as Return Loss, Radiation Pattern in 2D and 3D, VSWR, Field Directivity, Total Power Efficiency, Current Distribution and Total Field gain using IE3D EM software.

Split ring resonator loaded EF-structured left-handed metamaterial for modern electronic communications

A novel miniaturised EF-structured metamaterial loaded with split ring resonator (SRR) has been developed and investigated for multi-band frequency applications. Miniaturisation is achieved by increasing the metallic strips to form EF-structure resonator. Commercially available, the advanced electromagnetic simulator has been utilised for the layout design and elaborated analysis of this developed left-handed metamaterial. The unit cell structure is embedded in low-cost FR4 dielectric substrate and size of the metamaterial is 11.11 × 11.11 mm2. Due to the miniaturised size, a highly effective medium ratio of about 14.82 is obtained. The developed left-handed metamaterial exhibits negative permittivity, negative permeability, and negative refractive index over multiple frequency ranges. Nicolson-Ross-Weir (NRW) method has been utilised for the extraction of the effective parameters. Thus, a novel metamaterial has been presented where the miniaturised size and its performances makes it compatible to use for the applications of 1.82 GHz, 2.22 GHz, 4.82 GHz, 5.89 GHz, 10.54 GHz, i.e. for digital cellular system (DCS), earth exploration-satellite communications (EESC), lower band 5G mobile communications, WiMAX applications, and military satellite applications, respectively. Furthermore, the metamaterial has average SAR reduction of about 44%. These results proceed to a guideway of better SAR reduction of modern electronic communications.

Design and Fabrication of a Novel Compact Low-loss Microstrip Diplexer for WCDMA and WiMAX Applications

In this paper, a novel miniaturized microstrip diplexer using two bandpass filters (BPFs) is designed and fabricated. The filters consist of stub loaded coupled lines. Additional stubs and T-shape feeding structures are added to miniaturize the size of the presented diplexer. With the adopted special structure, low insertion losses and compact size are obtained. The introduced diplexer operates at 2.12 GHz for WCDMA application and 3.94 GHz for WiMAX application. The obtained insertion losses are 0.25 dB at 2.12 GHz and 0.26 dB at 3.94 GHz. A design technique for analyzing the proposed resonator is introduced to tune the resonance frequencies and obtain a compact size. The size of the proposed diplexer is 23.4 × 16.9 mm 2 (0.038 λ g 2 ). The measurement result of the fabricated diplexer validates the design technique and simulation results.

A Multiband Antenna For Gsm, Wlan, S-Band Radar And Wimax Applications

The futuristic technologies needs the low profile and compact multiband antenna for their applications as the size of the communication devices are reducing significantly. In this manuscript, a patch antenna is intended over Flame Retardant (FR4) substrate and then Defected Ground Structure (DGS) as well as Defected Microstrip Structure (DMS) were introduced in it, which increases the number of resonant frequencies and their return loss. Coaxial feed was utilized in this plan. The designed antenna radiates efficiently for the applications like Global System for Mobile Communications (GSM) at 1.8 GHz resonant frequency, WLAN with 2.4 GHz resonant frequency, S-Band Radar by means of 2.9 GHz resonant frequency and WiMAX standard by the side of 3.4 GHz resonant frequency. High Frequency Structural Simulator (HFSS) was utilized for the simulation of the projected antenna design.

Pattern reconfigurable Yagi‐Uda antenna with seven switchable beams for WiMAX application

AbstractIn this paper, a pattern reconfigurable printed Yagi‐Uda antenna with linear polarization is presented. The proposed design consists of three parts, including a driving element centered between two other parasitic elements. To achieve pattern reconfigurability, the approach of Yagi‐Uda configuration is employed, where the positions of the director and reflector are exchanged using PIN diodes. The proposed antenna employing six PIN diodes is designed to radiate the main beam at seven scanning angles (−60°, −40°, −20°, 0°, 20°, 40°, and 60°). The beam tilt depends on the size of the antenna's partial ground plane. The proposed design is simple in structure realized on a single substrate board of dimensions 75 × 70 mm2. The measured peak directivity obtained at various scanning angles is about 6.5 dB. The simulated and measured results are in good agreement. The proposed reconfigurable antenna is suitable for WiMAX applications operating around the frequency of 3.6 GHz.

Implementation of Metamaterial Loading to Miniaturized UWB Dipole Antenna for WLAN and WiMAX Applications with Tunability Characteristics

This paper presents a double-printed circular slot inscribed, hexagonal shape miniaturized dipole antenna featuring the ultra-wideband (UWB) characteristics with the implementation of linearly tapered feedline. The miniaturized UWB dipole antenna is designed for wireless applications wireless local area network (WLAN) and WiMAX by introducing a proposed metamaterial unit cell. Further, in comparison with the conventional UWB dipole antenna, miniaturization is achieved up to 35.89% and 16.67% with respective active patch area and antenna volume, respectively. The electrical dimension of the proposed antenna is 0.299 λ × 0.4385 λ × 0.0159 λ, of course, at lower frequency of 2.99 GHz. The use of metamaterial rectangular split-ring resonator and slotted ground structure witnessed the band achievements for wireless standards WLAN and WiMAX. The proposed structure is fabricated on FR4 substrate and tested. Impedance bandwidth of proposed antenna is obtained about 7.26% (2.39–2.57 GHz), 25.23% (2.91–3.75 GHz), and 16.92% (4.87–5.77 GHz) under simulation and 11.49% (2.38–2.67 GHz), 24.48% (2.94–3.76 GHz), and 15.99% (4.95–5.81 GHz) in measurement for WLAN (2.4–2.5, 5.150–5.250, and 5.725–5.825 GHz) and WiMAX (3.3–3.8 GHz) bands, respectively. Tunability between the wireless standards is demonstrated with the help of PIN diodes. The proposed design achieved high average gain of 3.31 and 2.06 dBi for simulation and measurement, respectively. The peak average radiation efficiency of 82.9% is observed during measurement mode. Experimental results are in good agreement with those obtained in the simulation of the proposed antenna.

Bandwidth and gain enhancement of microstrip antenna by frequency selective surface for WLAN, WiMAX applications

The research work presents a broad band with enhanced gain FSS based microstrip patch antenna for wireless communication. Three different antennas results are investigated to obtain proposed antenna. The designed antennas are E shaped patch, combined E and T shaped patch and combined E and T shaped patch with frequency selective surface (FSS). The proposed antenna is obtained by combined E and T shaped radiating patches with FSS under the modified ground plane. U shaped slit with multiple number of slots are loaded on the ground plane. The broad bandwidth of 6.4 GHz (2.9–9.3 GHz) with 8.12 dBi gain is achieved which is 5.12 dBi greater than the proposed E and T shaped patch (without FSS) antenna. The proposed patch antenna without FSS is fabricated and measured to validate the work. The designed antenna is very much applicable in wireless communication systems. It is specially designed for WiMAX (3.5/5.8 GHz) and WLAN (3.6/4.9/5/5.9 GHz) applications.

Circularly-Polarized and High-Efficiency Microstrip Antenna with C-Shaped Stub for WLAN and WiMAX Applications

In this article a novel planar triple-band microstrip monopole antenna with circular polarization and high efficiency is presented for wireless communications applications. This antenna with passbands at 2.4, 3.5, and 5.5 GHz is able to cover WLAN and WiMAX applications according to the IEEE 802.11b/g and IEEE 802.16 standards. The proposed antenna consists of a C-shaped stub to control the circular polarization and an inverted triangular patch which has two slots to achieve mentioned frequency bands. The proposed monopole antenna with dimensions 40×47×1.6 mm is implemented on the FR4 substrate and fed by a 50 Ω microstrip line. Parametric study for antenna dimensions and measurement results are presented in the article. The S-parameters of less than −10 dB, efficiency above 90% and omnidirectional radiation patterns are obtained in the proposed antenna. A brief comparison is made on the characteristics of the proposed antenna and other antennas presented in the articles and the results are presented.

Probe Feed Multi-Element Multi-Segment Triangular Dielectric Resonator Antenna with RCS Analysis

The aim of the paper is to propose a design and analysis of multi-element multi-segment triangular dielectric resonator antenna (MEMS TDRA) with Radar Cross-Section (RCS). The proposed antenna has been excited through coaxial probe feed. The coaxial probe feed excites TM[Formula: see text] dominant mode fields within the TDR elements. A general guideline for wide bandwidth and high gain has been prepared for designing of MEMS TDRA. The model of the proposed MEMS TDRA has been studied through simulation (Ansoft HFSS software) and fabricated for measurement. The simulated antenna performance has good agreement with the measured one. The proposed MEMS TDRA performance has been compared with some similar type of previously published structure and found wider bandwidth and higher gain. The proposed MEMS TDRA provides monopole-like radiation pattern with nearly 39% bandwidth ([Formula: see text] dB). The average gain of 6.0 dBi has been found over the entire bandwidth. The RCS analysis has been performed for monostatic and bistatic modes at different frequencies and angles. The proposed antenna is appropriate for WLAN and WiMAX applications.

Design of New Multiband Slot Antennas for Wi-Fi Devices

Microstrip antennas cover a wide range of application in different areas, such as internet services, mobile communication, and satellite navigation. Microstrip antenna consists of two metal layers and a substrate. In the two metal layers, the top one is called patch and the bottom layer is called ground. Between the patch and the ground, there is the substrate layer, which has a certain dielectric constant and thickness. The aim of this paper is to present a way of getting multi-band antennas for Wi-Fi devices. 2.5 GHz (2.5-2.69GHZ), 3.5 GHz (3.3-3.8GHz) and 5 GHz (5.25-5.85GHz) have been used for Wi-MAX applications. HFSS software has been used for simulation process. The multiband slot antennas have been simulated and manufactured. Multi-band microstrip antennas have been designed and simulated in terms of the return loss (S11) and the gain. These designs have been fabricated and their return loss has been measured and compared with the simulation results.

Multiband Microstrip Patch Antennas using Heterogeneous Substrate for Wireless Applications

A heterogeneous substrate multiband microstrip patch antenna with various shapes fed by a rectangular microstrip feed line is proposed in this paper with a total area of 73.3 x 127.85 x 3.2 mm3. The antennas are printed on a heterogeneous substrate with the combinations of easily available materials like FR4_epoxy, Air and Taconic RF-30 with relative permittivity of 4.4, 1 and 3.The multiband characteristics are achieved by choosing a proper selection of positions and dimensions of slot in the substrate below the patch. The various structures of microstrip patch antennas like rectangular, square, circular, elliptical and triangular covers L (1-2 GHz), S (2-4 GHz), C (4-8 GHz) and X (8-12 GHz) bands and used for various applications like Low Density Radio Communications Link (LDRCL), Communication satellites, Wireless LAN-802.11b, 802.11g, Bluetooth and WiMAX applications. All the antennas are designed and imitated using Ansoft HFSS 13.0 antenna software. The prototype of various shapes of proposed antennas are fabricated and measured and results in good return Loss, VSWR, resonant frequency, radiation pattern and the antenna gain.

Design and Performance Characteristics of Ircular Microstrip Patch Antenna Arrays

In wireless communication era, we need the antennas with low profile, light weight, planar but can meet the characteristics of non-planar structures, with ease of fabrication, flexibility in terms of electromagnetic parameters like radiation pattern, gain, impedance, polarization etc. Microstrip patch antennas, which come at low cost, size, good performance, ease of installation and easy integration to circuits, high efficiency, are suitable in that context. The Principle of slot is used on the patch which decreases the radius of the circular patch antenna, so as to reduce the size. In this work various Ircular microstrip patch antenna arrays are intended for the application of WLAN and Wi-Max at 2.4GHz for the improvement of gain. Single microstrip patch antenna and planar arrays of 1x2 and 2x2 ircular microstrip patch antennas are designed using strip line feeding technique and simulated on FR4 substrate. The planar antenna arrays are simulated using the High Frequency Structure Simulator (HFSS) software version v17.2 and the parameters like gain, return loss, Bandwidth and VSWR are evaluated at 2.4GHz frequency and the same are presented.

Dual band circular polarized bow tie slotted patch antenna over high impedance surface for WiMAX application

AbstractA novel planar dual-band bow-tie slotted patch antenna backed by high-impedance surface (HIS) is designed at 2.5 and 3.5 GHz for wireless application. The antenna employs coplanar waveguide fed patch and bow-tie slot as radiating elements. The bow-tie slot enables dual-band operation for the antenna. The HIS is made asymmetric in design to make it polarization dependent. This polarization-dependent HIS is eventually designed to reflect circularly polarized waves from linearly polarized incident waves.