Abdul Rani Othman

Study and Simulation of an Edge Couple Split Ring Resonator (Ec-SRR) on Truncated Pyramidal Microwave Absorber

Split ring resonator (SRR) structure can potentially be incorporated onto the truncated pyramidal microwave absorber. This study considers three difierent patterns of edge couple split ring resonator (EC-SRR) designs. Each EC-SRR design is then placed onto the truncated pyramidal microwave absorber. Outer split gap dimension widths of the EC-SRR are varied, and the various S21 performances are compared. This EC-SRR truncated pyramidal microwave absorber is simulated using CST Microwave Studio simulation software. The study and simulation are performed in low frequency range (0.01GHz to 1GHz) as well as in microwave frequencies range (1GHz to 20GHz). Simulation results of this EC- SRR show improvement of re∞ection loss and S11 performance in the high frequency range of the pyramidal truncated microwave absorber.

RUBBER TIRE DUST-RICE HUSK PYRAMIDAL MICROWAVE ABSORBER

Rubber tire dust-rice husk is an innovation in improving the design of pyramidal microwave absorbers to be used in radio frequency (RF) anechoic chambers. An RF anechoic chamber is a shielded room covered with absorbers to eliminate unwanted re∞ection signals. To design the pyramidal microwave absorber, rice husk will be added to rubber tire dust since the study shows that both have high percentages of carbon. This innovative material combination will be investigated to determine the best re∞ectivity or re∞ection loss performance of pyramidal microwave absorbers. Carbon is the most important element that must be in the absorber in order to help the absorption of unwanted microwave signals. In the commercial

Effect of single complimentary split ring resonator structure on microstrip patch antenna design

This paper had been comparing the performance of the normal patch antenna with single complimentary SRR patch antenna. Four different shapes of single complimentary split ring resonator structure had been incorporated into the microstrip patch antenna - square, circular, triangular, and rhombic. This simulation works had been done in CST Microwave Studio simulation software. The operating frequency of this antenna is 2.40 GHz for Wireless Local Area Network (WLAN) application. The parameters that considered in these works are return loss, resonant frequency, input impedance, gain, radiation pattern and bandwidth. The focusing parameter is to achieve the best gain performance that obtained from the single complimentary split ring resonator patch antenna. The addition of square SRR onto patch antenna will improve the gain from 6.334 dB to 6.508 dB.

5.75 GHz microstrip bandpass filter for ISM band

This paper presents on 5.75 GHz bandpass filter based on IEEE802.11a standard for wireless LAN application. The development of bandpass filter includes calculation, simulation, testing and measurement of the filter parameters process has been presented. Simulation software for this project used Ansoft Designer software. The filter operates at center frequency of 5.75 GHz with 100 MHz bandwidth and insertion loss below 10 dB. The bandpass filter contributes to the application of direct conversion front-end receiver for WLAN application at 508 GHz frequency.

A review of Substrate Integrated Waveguide (SIW) bandpass filter based on different method and design

Substrate Integrated Waveguide (SIW) is an emerging technology of high-frequency integrated that appeared in recent years which provides an excellent platform in order to design millimeter wave circuits such as filters, resonators and antennae. It offers advantages in terms of compact size and easy to integrate with the other planar circuit. The fabrication can be done by using standard printed circuit (PCB) where the cost of the manufacturing process will be reduced compared to the conventional waveguide filter. This paper presents the review of SIW bandpass filter for X-band applications for the past few years that have operation frequency from 8.2-12.4 GHz. Most researchers focus on designing SIW bandpass filter rather than other filter because Chebychev filter response is easy to make circuit synthesis. Different types of method have been introduced in the SIW bandpass filter design and the performance of the filter design will be compared.

Tri-band Minkowski Island patch antenna with complementary split ring resonator at the ground plane

The Minkoski Island patch antenna with complementary split ring resonator at the ground plane are proposed in this work. At the first stage, the normal square patch antennas mainly designed. Then, the Minkowski patch antenna was designed using 1st iteration technique and 2nd iteration technique. The Minkowski fractal shape slot was embedded in the center of the patch to form a Minkowski Island patch antenna. The next step is to apply the partial ground technique and embed the split ring resonator at the ground plane. This antenna was operating in tri-band frequency that is at 2.400 GHz, 3.500 GHz and 5.200 GHz with a return loss of - 11.868 dB, - 13.554 dB and - 18.112 dB respectively. The gain measured of this antenna is 1.286 dB, 1.410 dB and 3.945 dB.

Development of ultra-wideband (UWB) horn antenna using approximation method

This paper presents a design of an ultra wide-band (UWB) horn antenna for microwave imaging radar system. The key purpose of the study is to design a horn antenna which is used in medical imaging system. The proposed antenna operates within 3.1-10.6 GHz as it is the band allocated for medical industry usage. The antenna known as a directional antenna which is supported by rectangular waveguide. The horn antenna is purposely chosen to design in order to increase the directivity of the antenna within 15-20 dB and achieve higher gain and wider bandwidth as possible. This horn antenna is capable to produce return loss as minimum as possible. The antenna is designed and simulated using CST Microwave Studio. The simulation results show that the pyramidal horn antenna structure exhibits low VSWR as well as good radiation pattern over 3.1-10.6 GHz frequency band.

A compact DMS triple-band bandstop filter with U-slots for communication systems

This paper presents compact structure of bandstop filter with Defected Microstrip Structure (DMS) to produce a triple - band reject response. To prove the concept of the narrow notched DMS, the operating on centre frequency of 4.0 GHz is demonstrated and validated through simulation. The DMS structure is embedded in the middle of transmission lines in order to reject any undesired signals which may interfere with any communication systems. The design was simulated based on Roger Duroid RO4350B with a thickness of 0.508 mm and dielectric constant of 3.48. This type of filter is useful in any RF/ microwave communication systems, particularly to eliminate any undesired signals in wideband spectrum. While maintaining its excellent performance, the overall physical and cost reduction can also be achieved using this technique.

Design and fabrication of X-band Substrate Integrated Waveguide directional coupler

The compact size of four-port Substrate Integrated Waveguide (SIW) directional coupler designed for X-band application have been simulated and fabricated. The millimeter-wave circuits such as resonator, filter, coupler, power divider and the antenna can be designed by using SIW techniques. This technique appears the past few years and having the smaller size of circuits. It can straightforwardly integrate with the other planar circuit. Ordinary Printed Circuit Board (PCB) method can be utilized in order to complete the fabrication process. The cost of the manufacturing process for SIW is lower compared by using conventional waveguide. Usually, implementation of the directional coupler can be seen at satellite, radar and point-to-point radio. The simulations and measurement of this coupler design have shown the great performances by having the low insertion loss and return loss. Moreover, it also has high isolation and broad operational bandwidth.

The Cascode and Cascaded Techniques LNA at 5.8GHz Using T-Matching Network for WiMAX Applications

This project presents the cascode and cascaded techniques LNA at 5.8GHz using T-matching network applicable for WIMAX application. The amplifier uses FHX76LP Low Noise SuperHEMT FET. The LNA designed used T-matching network consisting of lump element reactive element at the input and the output terminal. The cascode and cascaded low noise amplifier (LNA) produced gain of 52.4dB and noise figure (NF) of 1.3dB. The input reflection (S11) and output return loss (S22) are -19.71dB and -10.07dB respectively. The bandwidth of the amplifier is more than 1.24GHz. The input sensitivity is compliant with the IEEE 802.16 standards.