design and analysis of microstrip antennas for wireless communications

Abstract

ABSTRACT newline newlineThe progress in modern wireless communication systems has increased dramatically the demand for microstrip antennas, capable to be embedded in portable, handheld devices such as RFID handheld reader, devices which provide a wireless network. Recently, demands of these devices with smaller in size and therefore antennas required smaller and light weight especially at the low microwave frequency range. The microstrip antennas can be designed in very small size with lower gain and bandwidth. For portable and handheld devices, gain and bandwidth of the antenna is not so important. However, the antenna meets some gain with desired bandwidth constraint. For millimeter wave applications, the antenna has to be high gain with broadband impedance bandwidth. The microstrip patch antennas are similar to parallel plate capacitors. As capacitor contains two metallic parallel plates between which there is dielectric substrate whereas in microstrip patch antenna one side of the dielectric substrate has metallic plate of infinitely extend to form the ground plane and the other side acts as radiating patch. The size of the patch depends on the wavelength of radiating signal. The patch of the antenna is generally made of conducting materials such as copper or gold and can be of any size and shape depending on the radiating frequency. The microstrip patch antenna can fulfil the demand of various wireless applications. newline In this thesis work, it is aimed to develop dual band, wide band, and broad band characteristics of the microstrip patch antenna. The antenna performance will be analyzed by varying the antenna parameters. Various antenna parameters such as reflection coefficient, return loss and VSWR will be studied theoretically and compared with the simulated results as well as experimental results. Antenna performance and improvement in band width with conventional antenna can be studied and analyzed. newline newline newlineKeyword: Microstrip, Reflection coefficient, Substrate, Rad