Radiation characteristics of rectangular patch antennas with a laminated ground plane

In modern aeronautical and automobile industries, composite materials are becoming increasingly popular for building the vehicular surface. The antenna engineer may face the situation of needing to design patch radiators above the composite material instead of a conductor ground plane. The input impedance and radiation patterns of a rectangular patch antenna attached to a laminated ground plane by using an integral equation approach is studied herein. The effects of composite lamina, substrate thickness and current probe location on the input impedance and radiation patterns are analysed. It is observed that the bandwidth of the patch antenna can be increased significantly when the substrate thickness is reduced. This observation is contrary to the conventional microstrip antenna concept and can be used to design a wideband microstrip radiator