H. A. Bakar

Performance Enhancement of Inverted Suspended Circular Polarized Antenna with the Integration of Metasurfaces (MS) Structure Technique

In this paper, it is proposed to use metasurface (MS) structure for the miniaturization and antenna performance enhancement of inverted suspended circular patch with square slot. The antenna was designed based on inverted suspended circular patch with air gap between the patch substrate and copper ground plane is separated with distance of 10 mm (Design A). L-probe technique is used for the antenna design and by using Design A the MS structure is put at the top of the antenna with air gap separation of 1 mm (Design B). The proposed antenna had been designed and simulated by using Computer Simulation Technology (CST) Software. Target application for this antenna design is for Wireless Local Area Network (WLAN) at operating frequency of 2.4 GHz. Simulation and measurement antenna performances in term of return loss, resonant frequency, bandwidth, realized gain, directivity, axial ratio, total efficiency and radiation pattern at the design frequency are investigated and discussed. Based on the result, with the integration of MS, Design B antenna substrate size can be reduced by 23.45 %, yet maintaining the similar performance. Other than that, axial ratio bandwidth (ARBW) for Design B also increases up to 68.8 % from 58.4% (Design A) with impedance bandwidth 627 MHz which is 71 MHz wider than Design A.

Design of Circular Polarized Antenna by Using Inverted Suspended Circular Patch Design for WLAN Application at 2.4 GHz

In this paper, an inverted suspended circular patch antenna with circular polarization is proposed for wireless local area network (WLAN) operating at 2.4 GHz frequency. The antenna was designed based on inverted suspended circular patch with an air gap between substrate and ground plane layer at distance of 10 mm. L-probe technique is used in this antenna design in order to feed the signal from SMA probe to the feedline of the circular patch structure. The design and simulation process are done by using Computer Simulation Technology (CST) software. Antenna performances in term of return loss, resonant frequency, bandwidth, gain, directivity, axial ratio, total efficiency and radiation pattern at 2.4 GHz frequency are discussed. The comparison result of simulation and measurement show that the proposed circular polarized antenna obtained bandwidth more than 100 MHz with gain and return loss achieved more than 5 dB and -13 dB at 2.4 GHz.

Investigation of Circular Patch Metasurface (MS) on Inverted Suspended Circular Polarized Antenna

In this paper, an analysis of different stage of circle patch metasurface (MS) on basic structure of inverted suspended circular patch with square slot antenna design is proposed to investigate its effect toward the basic antenna performance. The basic antenna was designed based on inverted suspended circular patch with air gap separation between the patch substrate and copper ground plane at a distance of 10 mm (Basic design). Then, different design of MS structure (Design A, B, C & D) consisting of 5 x 5 unit cell of homogeneous periodic element is place in between the air gap of the basic antenna. All of MS design is located at a fixed position to study the effect of different MS shape to the Basic antenna performance. The proposed antenna and MS structure had been designed and simulated by using Computer Simulation Technology (CST) Software. Target application for this antenna design is for Wireless Local Area Network (WLAN) at operating frequency of 2.4 GHz. Simulation performances in term of return loss, resonant frequency, bandwidth, realized gain, directivity, axial ratio, total efficiency and radiation pattern at the design frequency are investigated and discussed. From observation on simulation result, resonant frequency of Basic design is shifting to a lower frequency from 2.4 GHz to 2.19 GHz (Design C and D) with the integration of the MS structure. Design C obtained the widest axial ratio bandwidth among all of other design with 1380 MHz covered from 1.31 GHz to 2.69 GHz. Directivity for Basic designs at 2.4 GHz increases from 7.94 dBi to 8.17 dBi, 8.16 dBi, 8.15 dBi and 8.06 dBi (Design A, B, C and D) respectively.

Single linear-polarized and single circular-polarized slot antenna for WLAN application

This project proposed a single linear-polarized and a single circular-polarized patch antenna are design for WLAN applications at 2.4 GHz. This antenna is using FR-4 substrate with permittivity, εr = 4.4 and the electrical conductivity tangent loss, tan Δ = 0.019. Three design antennas with same dimension size but with different feed line configuration had been consider as Design A, Design B and Design C. Design A and C have a better measured return loss of − 25.38 dB and − 24.384 dB, respectively. Beside that the Design B shows the performance of − 15.976 dB only.