Dual-Polarized Feed-Cluster for a Reflector-Based Multi-Beam Sar Antenna

EADS Astrium GmbH and Saab Space AB have designed, developed and bread-boarded a feed-cluster subsystem for a reflector-based multiple beam SAR antenna in X-Band. Flexible active phased SAR antennas are used for wide swath coverage with Envisat and TerraSAR-X as examples. Such active phased arrays are complex and still very costly. Simpler solutions with less flexibility and less wide coverage can be provided by reflector-based SAR antennas with somewhat reduced coverage. A study and development activity under ESA contract focused on a design of such antenna and a design, development, bread-boarding and testing of a dual polarized feed-cluster. Results have been used to demonstrate accurate feasibility of the reflector-based SAR antenna design, exploiting the multi-pencil-beam approach (European Patent EP1471600). The designed dual-polarized SAR antenna allows for Stripmap and ScanSAR operation over limited angular coverage around an installable pointing direction.