Bandwidth-enhancement of circularly-polarized fabry-perot antenna using single-layer partially reflective surface

Abstract

In this article, we investigate bandwidth-enhancement of a circularly-polarized (CP) Fabry-Perot antenna (FPA) using single-layer partially reflective surface (PRS). The FPA is composed of a single-feed truncated-corner square patch antenna, which is covered by the PRS formed by a square aperture array. We revealed that the finite-sized PRS produces extra resonances and CP radiations for the antenna system, which broadened the impedance matching and axial ratio (AR) bandwidths significantly. For verification, a broadband CP FPA prototype operating near 5.8 GHz was realized and tested. The fabricated antenna with overall size of 125 mm x 125 mm x 23.5 mm achieves a |S-11| < -10 dB bandwidth of 31.7% (5.23-7.2 GHz), an AR < 3-dB bandwidth of 13.7% (5.45-6.25 GHz), the peak gain of 13.3 dBic, a 3-dB gain bandwidth of 22.38% (5.0-6.26 GHz), and a radiation efficiency of >91%.