Gain Enhancement in a Fabry-Perot Cavity Antenna using Phase Correcting Miniaturised FSS

This paper investigates a method to enhance the radiation pattern of a Fabry – Perot cavity antenna (FPCA) through the use of frequency selective surfaces (FSS) to improve aperture phase distribution. Four FSS sheets were used as walls of a fully enclosed FPCA operating at 2 GHz. Electromagnetic rays at the edge of the FPCA incur a phase change when reflected off the FSS walls making the complete aperture phase distribution more uniform thereby increasing directivity. Simulations demonstrated that the phase correcting FSS walls significantly enhance the directive radiation properties of the FPCA. This includes a 2.1 dBi increase in peak directivity, and a 14.3 % reduction in 3 dB beamwidth (from 42° to 36°).