Right-Hand/Left-Hand Circularly Polarized High-Gain Antennas Using Partially Reflective Surfaces

Single-feed, efficient, high-gain antennas using partially reflective surface (PRS) with right-hand/left-hand circular polarization (CP) are investigated. Metallic ground plane and a PRS with square patch (SP) arrays at about 0.5λ0 height form the Fabry-Perot cavity (FPC) that is fed by a circularly polarized microstrip antenna (MSA). Right-handed circular polarization (RHCP) or left-handed circular polarization (LHCP) at the MSA is obtained using a single diagonal feed and shorting posts along x- or y-axes. Constant high-gain performance is obtained by resonating feed patch (FP) and SP arrays in the same frequency band. The effect of the SP array on antenna performance is critically analyzed. Gain enhancement of 10 dB over the circularly polarized MSA is obtained by optimizing PRS structures. Antennas with different PRSs yield peak gain of 9.1-17.3 dBi, and axial ratio (AR) is less than 3 dB over the desired frequency band. Gain variation is less than 1 dB over the frequency band. Measured results validate the design concept and indicate that the proposed structures exhibit good radiation characteristics and are suitable for satellite systems.