Dual-Band Dual-Circularly Polarized Structure Reused Shared-Aperture Antenna for Satellite Communication

An S/Ka dual-band dual-circularly polarized shared-aperture antenna is proposed in this paper. In the Ka-band, a wide phase-shifting circularly polarized reflection element is designed, with a maximum compensation phase of up to 500°. The elements are arranged periodically to form a high gain reflectarray, and the linearly polarized horn is used as the feed to achieve right-handed circular polarization characteristic. In the S-band, the metal ground of the reflectarray is reused as the microwave antenna radiator, and the left-handed circular polarization characteristic is obtained by using a double-feed. The antenna is processed and its performance is verified. The measurement results show that the impedance bandwidth of the S-band is 2.04-2.1 GHz, and that of the Ka-band is 28-31 GHz. The port isolation exceeds 30 dB in both bands. The gain of the S-band can reach 6.8 dBic, Ka-band can reach 21.2 dBic, and the aperture efficiency is 51.8%. It has application prospects in satellite communication systems.