DESIGN OF APERTURE COUPLED M1CROSTRIP ANTENNA WITH L- SHAPED COUPLING SLOT FOR WIDEBAND CIRCULAR POLARIZATION

Abstract

Owing to the advent of wireless communication systems, such as Bluetooth and WLAN, there has been a greater attention drawn towards the development of the low cost integrated antennas. At the same time, the use of personal handheld telecommunication devices has significantly increased around the world. The fast growing market for these devices has led to the dramatic increase in the demand of antenna. This made the design and development cycle of the antenna quite compressed and a challenging task. In this dissertation, the design and its realization of a single feed, aperture coupled microstrip antenna with circular polarization is described. Here wide band circular polarization has been achieved with the L—shape coupling slot having a perturbation which supports additional resonances when stacked with the patch having a slot. The antenna structure supports Left Hand Circular Polarization (LHCP). The simulated 3—dB axial ratio bandwidth achieved is 13.7 % with centre frequency at 2.47 GHz and the measured value is .- 10.5%. A 2 x 2 sequentially rotated sub—array is designed and fabricated. A 20 % axial ratio bandwidth has been obtained from the simulated 2 x 2 sub—array and N 17.39% was obtained experimentally.