Development of broadband circular polarized planar antenna for "EROS" LEO satellite

This paper describes the development, implementation and prototype test results of a broadband circularly polarized planar array antenna, operating at X-band. The antenna is intended for downlink implementation in the "EROS" series of LEO satellites. The antenna position is controlled by a two-axis antenna pointing mechanism (APM). It directs the antenna main beam towards the ground station. Antenna concept considerations and performance optimization-minded design processes are elaborated. The prototype measurement results are commented upon as well. The antenna main design goals were to achieve simultaneous broadband gain and low axial ratio operation within the structural constraints and facing the extreme LEO satellite open space environmental conditions. At the time of paper preparation, the first "EROS" satellite has been successfully launched. Satellite transmission signals, evaluated by the ground station receiver, confirmed successful antenna operation in open space. The measured performance matched that predicted by the design.