Wideband Circularly Polarized Stacked Microstrip Antennas

A simple technique is developed to improve the axial ratio (AR)-bandwidth and quality of circularly polarized stacked microstrip antennas (CPSMAs) using a new C-type single feed. The proposed antenna has been optimized and fabricated, and the computed results agree very well with measurements. The antenna has a 3 dB AR bandwidth of 13.5%, gain is more than 7.5 dBi over the 3 dB AR bandwidth and the 10 dB return-loss bandwidth is 21%. The proposed feed optimization technique is useful for rapid design of circular polarized stacked microstrip antennas.