A Telemetry, Tracking, and Command Antennas System for Small-Satellite Applications

Circularly polarized (CP) antennas are used in space applications for telemetry tracking and command (TT&C). In this paper, we present an antenna for a TT&C system that can employ only four antennas to achieve a wide quasi-isotropic coverage. The proposed single-feed circular polarized annular patch antenna is low profile and compact. It exhibits a wide impedance bandwidth of 19.7%, wide-angle circular polarization with an on-axis maximum gain higher than 6 dBi and an axial ratio below 4 dB in the frequency band 2.0–2.3 GHz. The developed low-cost antenna can be used for small-satellite data downlink where only two right hand circular polarized (RHCP) antennas and two left hand circular polarized (LHCP) antennas would be required since each antenna has an adequate CP gain on a wide angle. A prototype antenna has been fabricated and measured. The experimental validation shows a good agreement of the measured impedance bandwidth, axial ratio, and far-field pattern with the ones predicted by numerical full-wave study.