INTRODUCTION
Microstrip antenna has gain popularity of their small size and light weight
however a limitation of microstrip antenna is the narrow bandwidth of the basic
element. The bandwidth of basic patch element is usually 1-3%. The bandwidth of
antenna is defined [1] as the range of frequencies over which the performance of
the antenna with respect to some characteristics confirms to a specified standard.
The bandwidth of the antenna depends on patch shape, resonant frequency,
dielectric constant and the thickness of the substrate.
The bandwidth of an antenna can be increased by reducing the substrate
permittivity (εr) or increasing its thickness (h) [2]. However there are some
problems associated with increasing the substrate thickness. Here most of the
work done for bandwidth enhancement and multiband characteristic.