Analysis of a Rectangular Slot Antenna Loaded by a Dielectric Hemisphere with Double Dielectric Coatings

A rigorous analysis method is provided for a rectangular slot antenna loaded by a dielectric hemisphere with double dielectric coatings. The method is an integral equation approach and the moment method solution is sought. The antenna input impedance and radiation patterns are obtained and compared with the case with a single dielectric coating layer. The bandwidth of the antenna is found to be significantly improved with a second dielectric coating layer. The thickness of the second dielectric coating layer is found to be able to control the bandwidth, the impedance and the resonant frequency of the antenna. The low-profile radiation patterns and the enhanced bandwidth characteristic of the antenna is suggested to have a potential application in mobile base-station communications.