Design and Analysis of Microstrip Antenna for Circular Polarization

Abstract

In this work, novel microstrip antennas are proposed for various modem wireless applications such as WLAN, WiMAX, GPS, synthetic aperture radar, television broadcasting. navigation. non-geostationary satellite communication for L, S and C band applications. Various parameters of circularly polarized microstrip antennas are investigated practically and theoretically. The available literature related to circularly polarized microstrip antennas for various modem applications have been studied and investigated. Several limitations of circularly polarized microstrip antennas are resolved in this thesis work; i.e. enhancement of impedance and axial ratio bandwidth, improvement in gain, compactness in size. multiband performance and achieving circular polarization by using simple asymmetric slots. The optimization of all the proposed designs is conducted using finite element method based commercial software, Ansoft HFSS and found measured results are in close agreement with the theoretical and simulated results. newlineIn the thesis efforts have been done to design simple single fed compact antenna structures. A novel L-slot square microstrip patch antenna is proposed. The proposed structure can generate two orthogonal modes of equal amplitude and 90° relative phase shift; therefore, stub, notch or chamfering at corners of the square patch are not required making antenna design relatively simple. The proposed structure is simple to fabricate and is useful for designing compact circularly polarized antennas and arrays. This antenna may be a good choice for modem wireless applications which require miniaturized circularly polarized configuration to mitigate multipath fading effect in wireless communication environment. newlineThe L band antennas are miniaturized and light in weight, making them specifically suitable for tactical and mobile wireless operation. A novel compact sized circularly polarized microstrip antenna for indoor WLAN applications is proposed. The antenna structure consists of slits introduced at the boundary and...