Design of a Circularly Polarized Stacked Patch Antenna with Circular Ground Plane

A circularly polarized stacked patch antenna operating in L-Band is proposed for satellite communications, including the Global Navigation Satellite System (GNSS). The complete design process is presented, which consists of successive design steps described and motivated in the paper. Starting from a classical circular patch with dual 90-degree phased feed to achieve circular polarization, proper modifications are made in order to improve the antenna performance in terms of operational bandwidth and polarization purity so as to facilitate the transmission and reception of signals from satellites. The final antenna is a stacked patch consisting of a lower circular patch with circular ground plane and dual 90-degree phased feed, and an upper annular ring patch, separated by an air fill gap. Compared with a classical circular patch, the final proposal strongly extends the frequency range and improves the polarization purity, while maintaining relatively compact size and weight. Simulation results are provided while a prototype is currently being manufactured.