Wideband High-Gain Circularly Polarized Stacked Microstrip Antennas With an Optimized C-Type Feed and a Short Horn

A new technique is developed to increase the axial ratio (AR) bandwidth of circularly polarized stacked microstrip antennas (CPSMAs) to about 15.0% by optimizing the location of the C-type single feed and a few other parameters. The stacked microstrip antenna with a quasi-planar surface-mounted short horn (SMSH) has achieved 13 dBi gain, 15.5% 3 dB AR bandwidth, 0.37 dB minimum AR and 25.0% impedance bandwidth. The measured gain is more than 11.5 dBic over the impedance bandwidth. The proposed technique simplifies the design of wideband circularly polarized antenna for medium to high gain applications.