The INTELSAT-9 C-Band Hemi/Zone Antennas

The next generation of INTELSAT-9 spacecraft, the ENITELSAT-9 series, provides service in C and Ku-band. The feed arrays for the C-band multifeed reflector antennas are designed, manufactured and tested by Dorier Satellitensysteme GmbH in Munich, Germany. The antennas required for the C-band service must fulfil stringent requirements for gain and isolation in order to optimally utilise the frequency spectrm. Furthermore, in-orbit reconfigurability is required putting additional constraints on the design. For service in the Atlantic and Indian ocean regions two different designs evolved, driven by the different coverages and the reconfigurability requirements. The fmal designs feature as many as 126 feed horns and up to ten switches. The design process with multiple sultaneous constaints being accounted is described in this paper. The measurement results confirming the design performance at ambient as well as over temperature are also presented.