M. Z. A. Abd Aziz

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.

Investigation of dual and triple meander slot to microstrip patch antenna

A dual and triple microstrip meander slot antenna is presented for Wireless Local Area Network (WLAN) application. The antenna also has the potential to be used as the receiving antenna in an energy harvesting system. The proposed antenna comprises a rectangular microstrip patch element embedded with meander slots. The parametric study is performed to investigate the characteristic of microstrip patch antenna with double meandered slots compared to the same microstrip patch antenna with triple meandered slots. Microstrip patch antenna with dual meander slot can achieve return loss until -24.54dB. However the gain of the antenna, 1.46 dBi is lower than microstrip patch antenna with triple meander slot which is 4.28 dBi. Other antenna parameters are also investigated such as bandwidth, radiation patterns and directivity have been observed and simulated. Measurement results are also recorded in this paper.

X-Polarization array antenna with parallel feeding for WiMAX 3.55 GHz application

An X-Polarization array microstrip patch antenna for WiMAX application is introduced in this paper. The array antenna operates at WiMAX frequency of 3.55 GHz. The substrate used is FR-4 with the thickness of 1.6 mm, relative permittivity of 4.5 and loss tangent of 0.019. The antenna use parallel feeding network to feed all the eight elements with coaxial port. The array has gain of 6 dBi, and directivity 8.754 dBi. The array antenna only requires single input port unlike conventional X-Polarization array antenna that uses multiple input port application. Parametric study of cross angle to antenna performance is studied which have not been discussed in the past research and coupling between the elements in the array is presented.

Sierpinski carpet fractal antenna

This paper describes the design and fabrication of Sierpinski carpet fractal antenna. The investigation took place between ranges of 1GHz to 10 GHz. The fabricated Sierpinski carpet fractal antenna proves that it is capable to create multiband frequencies. There are six resonant frequencies appeared at 1.63 GHz, 4.99 GHz, 5.45 GHz, 7.68 GHz, 8.68 GHz and 9.99 GHz for second iteration. The radiation pattern shows the existing of side lobes especially at higher frequency. As the iteration increased, HPBW is still maintaining.

Dual-band monopole antenna for energy harvesting system

A planar dual-band monopole antenna is presented for Global System for Mobile Communications (GSM) band applications, which also have the potential to be used for energy harvesting system. The proposed antenna comprises of a ground plane at the back of the FR4 substrate and three microstrip lines which are physically connected with each other at the top surface of the substrate. The monopole antenna achieves good return loss at resonance frequencies of 915 MHz and 1800 MHz with a bandwidth value of 124.2 MHz and 196.9 MHz respectively. The antenna gains of 1.97 dB and 3.05 dB are achieved at resonance frequencies of 900 MHz and 1800 MHz. Experimental results show good agreement with simulated performance. The output from the receiving antenna is also observed in order to analyze the relationship of the power level and the distance between transmitting and receiving antenna. This study is an early investigation in designing the RF energy harvesting system to support green technology and sustainable development particularly for Wireless Sensor Network (WSN) applications.

Impedance modeling for a unit cell of the square loop frequency selective surface at 2.4 GHz

This paper presented an impedance modeling of the Equivalent Circuit (EC) for a unit cell of the square loop Frequency Selective Surface (FSS) structure. The unit cell of the square loop FSS is designed and simulated using the CST Microwave Studio software at 2.4 GHz based on industrial, scientific and medical bands (ISM) standard. The square loop FSS is simulated without FSS, with square FSS and FSS with slot. The investigation has been done on the length of substrate (s), width of substrate (w), length of square FSS (a) and length of slot (b). Imaginary (Im) component of EC has been modeled based on physical parameters of the square loop FSS in wavelength. EC gives a simple alternative method in FSS analyses which are useful for quickly predicting the performance of FSS.

Rectangular microstrip patch antenna based on resonant circuit approach

This paper presents the investigation based upon the resonant circuit approach to characterize the rectangular microstrip patch antenna from the low-pass prototype lumped element. The physical layout of the rectangular microstrip patch antenna based on single-mode and dual-mode will be established. An improvement on bandwidth of the antenna can be achieved by increasing the number of modes. In the paper, the understanding of microwave filter synthesis technique is applied in order to obtain the resonance at 2 GHz. A notch technique is used in the design to produce dual-mode frequencies on the microstrip patch antenna. The prototype circuit and proposed physical layout of the single and dual-mode microstrip patch antennas are demonstrated through the analysis of circuit and EM simulations in order to proof the proposed concept. This study would be useful to realize antenna for broadband applications as well as to investigate the appropriate technique for integrating antenna and microwave filter.

RF transmitter system design for Wireless Local Area Network bridge at 5725 to 5825 MHz

In data communication system, the outdoor of Wireless Local Area Network (WLAN) technology can be implemented in bridge connection. It allows LANs in separated buildings to be connected over the distance ranging in several hundred meters. In RF system design level, the performance of the WLAN bridge also relies on the RF transmitter system where it must be well designed to minimize the nonlinear distortions in the system. This paper presents a RF transmitter system design for WLAN bridge at 5725 - 5825 MHz based on IEEE 802.11a standard. Based on the calculation and simulation results, the RF transmitter can transmit maximum output power of 24 dBm with -25 dB constellation error at 54 Mbps data rate which is, comply with the standard. Beside that, the prototype of the RF transmitter without filters has been measured to verify with the simulation results in term of gain compression.

Butler matrix using circular and mitered bends at 2.4 GHz

This paper presents two designs of a four-port Butler matrix to feed a switched beam antenna array for wireless local area network (WLAN) at 2.4 GHz. The two methods applied in designing a beamforming network based on the Butler matrix are the circular and mitered bends. The circular design is larger while the mitered design is compact in size. The design developed has been simulated and the results have been compared to determine the performance between the two designs. The overall results prove that the Butler matrix designed with mitered bends performs better than the one with circular bends.

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.