Distortion measurement and compensation in a synthetic aperture radar phased-array antenna

This paper describes a metrology system for measuring deflection of a phased-array antenna panel. It will be implemented in a novel space-borne synthetic aperture radar system called WiSAR (Wireless Synthetic Aperture Radar). WiSAR uses a wireless signal interface between a boom-mounted space-feed antenna and a lightweight phased-array antenna panel. As a result of the flexible, light-weight antenna panel construction, MDA has developed the Antenna Distortion Measurement System (ADMS) to monitor any mechanical distortions of the antenna panel and allow the beam formation to be compensated accordingly. The system uses a series of markers (WiSense nodes) distributed over the antenna panel, and sequentially measures the position of each marker relative to the space-feed antenna. Once the antenna panel shape has been measured, the desired beam shape can be maintained by adjusting the phase shift of the active phased-array elements (WiNodes).