Design and Technology Aspects of Array-fed Large Reflector Based Multi-channel SAR Concept

Abstract:
Multi-channel SAR systems with digital beamforming capabilities are a key component of next generation SAR missions as they allow implementing advanced radar imaging techniques like simultaneous multiple beam in reception which in combination with staggered PRI operation mode provides an efficient way to overcome the classical SAR resolution-coverage trade-off giving response to applications demanding for larger wide swaths with high azimuth resolution and sensitivity. The presented work shows the design aspects of a digital beamforming SAR system concept based on large reflector antenna fed by a multichannel planar array antenna whose architecture is based on subarray overlapping technique. The paper describes the design and architecture of the SAR payload, the feedarray implementation details and reflector manufacturing aspects impacting RF performances. Finally SAR system performances have been derived to assess the proposed concept suitability for a reference L-band mission able to map 400km swath with 5 meter resolution in dual polarization mode.