Superconducting Circularly Polarized Antenna at 12 GHz: A Study with Single and Dual-Feeding Techniques

Superconducting microstrip antenna arrays are expected to be used in the satellite communication system which needs circularly polarized (CP) antenna with high gain and low axial ratio. We have studied the single patch CP antennas with single and dual-feed (reactive splitter coupled) structures to excite CP signals. Square patch elements with a center frequency at the proximity of 11.85 GHz and input impedance 50 Ω were used in the investigation. Measured results have been presented on the both types of antennas analyzed by a microwave simulator. Both superconducting (YBCO) and metal (Cu and Au) antennas have been considered for the comparison of antenna properties.