Abstract:A quadrifilar helical antenna equipped with chokes is designed in order to solve the problem of multipath interference in the complex satellite surface electromagnetic environment, and to meet the requirements of satellite high-speed data transmission for telemetry, track and command system. This antenna has two arms at equal amplitude and the feed at 90° phase difference. It works in the S-band, with half-space beam coverage, high gain, wide-angle circular polarization, small size, and light weight. The simulation and measurement results show that the circular polarization axis ratio of the antenna is less than 3 dB in the range of ±110° and the simulation results are in good agreement with measurement. A solution to the problem of multipath interference is also proposed in this paper. The gain and axis ratio of specific direction are adjusted to meet different requirements.