Development of High Aperture Efficiency Fabry-Perot Cavity Antenna System

A Fabry-Perot cavity antenna (FPCA) system with high efficiency is proposed. The design consists of a source antenna with a frequency selective surface (FSS). The source antenna is an aperture coupled microstrip slot antenna with cavity backing. The FSS is a square aperture with rectangular unit cells. The E-field in the near and far field is compared for the FPCA system and the source antenna without the FSS (i.e. source antenna only). The FPCA has low phase variation of approximately 10° in the E-plane compared to high sinusoidal phase variation of 90° of the source antenna. The far-field gain of the FPCA system is 11.3 dB, which is a 4.5 dB improvement of the source antenna gain. The aperture efficiency of the FPCA system is 84% compared to the source antenna efficiency of 30%.