Microwave Photonics Beamformer for Spaceborne SAR

Advanced SAR imaging modes benefit from the implementation of beamsteering capabilities in the SAR instrument. Beamsteering is typically achieved by RF analog, digital or hybrid approaches. With the latest advances of microwave photonics, specifically the photonic integrated circuit (PIC) technology, beamsteering implementations in the photonics domain offer an attractive alternative. Here, an innovative radar receiver based on PIC technology will be presented. The PIC implements precise, continuous beamforming-on-receive of wideband signals from a 12 antenna elements array, synthesising up to three simultaneous beams. The PIC also implements frequency-agnostic photonic down-conversion so that the synthesised beams can be directly digitized.