Contents I. Introduction
Microstrip patch antenna is built up in a similar way to a parallel plate capacitor. Both have two metal layers and a dielectric material in between the two metal layers. In a microstrip antenna, the lower conducting layer is called ground plane, the dielectric material (substrate) in the middle and finally conducting layer on the top called patch. The size of this patch depends on the wavelength and thus the microstrip patch antenna is classified as a resonant antenna. For this type of antennas the bandwidth is narrow, usually a few percent. To achieve wide bandwidth many broad banding techniques like using low permittivity thicker substrate, feeding techniques, stacked patches, parasitic arrangement of patches and the use of different shapes are also available [1]–[3]. But increasing the substrate thickness beyond some limit will cause surface wave excitation and the other techniques also have some drawbacks. Here we use parasitic arrangement of patches and low permittivity techniques.
