Design of Microstrip Antenna for Wireless Applications

Abstract

In this thesis, the focus is not in designing any antenna for a particular wireless application but a study on the existing antennas has been made and the methods by which their performance can be improved. The antennas chosen are the standard designs, ones which are most rampantly used in the wireless applications like the Bluetooth, Wi-Fi & Wireless LAN applications in the frequency range of 2.45GHz. An antenna was also designed taking into consideration the GSM band. The bandwidth of the antenna has been given special attention since data rate criterion have to be met apart from the resonant frequency. A circularly polarised antenna was also designed that could be optimised for GPS applications. Further in the thesis a Patch antenna calculator has been designed in MATLAB to reduce the repetitive task of finding the antenna dimension for a rectangular microstrip patch. A GUI has been developed using MATLAB GUIDE tool to provide a user-friendly interface. The calculations are done in the background for several antenna parameters using the cavity model for microstrip patch antenna. This GUI would be helpful in getting the basic idea about a few basic antenna parameters before the design, simulation and parametric analysis in software like CST Microwave Studio, HFSS and IE3D. To miniaturize the antennae further a metamaterial based approach has been incorporated. A comparative analysis of different conventional and metamaterial based microstrip patch antenna. A study of SRR based microstrip antenna and their equivalent circuits have been carried out. A unit cell of SRR has also been designed for the frequency of 10.25 GHz. Using such metamaterial unit cell a miniaturized microstrip patch antenna can be realised as per our requirements.