A classical method to disc microstrip antenna with arbitrary substrate

The microstrip antenna has aroused interest in a large area, especially with the development of satellite communications. Due to the inherent narrow bandwidth of the microstrip antenna, it is desirable to find methods to increase the bandwidth. It is wellknown that, by increasing the thickness of the dielectric substrate, the bandwidth of the antenna can be increased. However, most existing techniques for calculating the input impedance of microstrip disc antennas are only valid for thin substrates. The authors seek a new method to analyze the problem of input impedance of disc antennas with thicker substrates from a theoretical viewpoint