Design Of The Feed System For The Satellite Antenna On The Move

Mobile broadband communication signal can be transported in real time by intercommunication between the satellite antenna on the move and geostationary satellites.The feed system of the dual-circular-polarization satellite antenna on the move is presented in this paper. It includes three parts, the waveguide duplexer, the septum circular polarizer and the circular waveguide with a dielectric-plate variable polarizer inserted. Two waveguide duplexers are accomplished with mode-matching and numerical method. The size of the septum circular polarizer is optimized to satisfy the requirements of circular polarized radiation in the square port. The dielectric-plate variable polarizer is designed by simulation software HFSS. Finally, couplers are used to combine the above three parts.Some measurements for the feed system are done, with insertion loss of the system less than1.15dB, and isolation of the receiving and transmission ports more than70dB. Polarization characteristics of the antenna can be controlled by rotating the variable polarizer. It is shown that the feed system works well for the dual-circular-polarization satellite antenna on the move.