A Tri-Band Circularly Polarized Shared-Aperture Patch/Fabry–Pérot Antenna for Satellite Communication

This letter presents a tri-band circularly polarized (CP) shared-aperture Fabry–Pérot (FP) antenna/patch antenna. A dual-band partially reflective surface (PRS) unit is designed with different reflective characteristics in the C and Ku bands. The 10 × 10 PRS units function as a radiator in the L band. The L band patch and FP antennas share the same reflective ground and cavity. A dual-band CP patch antenna is designed to act as the feed of the FP antenna. The CP radiation of the L band is achieved by using a new structure to feed the PRS with a 90° phase difference. The measurements reveal that a common bandwidth of (|<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub>(22)| < −10 dB, gain reduction < 3 dB, AR < 3 dB) 1.09 GHz to 1.11 GHz, 7.43 GHz to 7.49 GHz, 13.5 GHz to 13.6 GHz, isolation higher than 30 dB, a peak gain of 8 dBi, 13.8 dBi, and 19.5 dBi at L, C, and Ku band, respectively. The frequency ratio and polarization of the three bands can be easily adjusted based on the same principle.