Theoretical and experimental investigation of large Microstrip array antenna design

During the last years several research and development programmes have been carried out by Saab Ericsson Space in the field of synthetic aperture radar (SAR) antennas for space applications. The aim has been to develop and evaluate different design concepts for future SAR applications. The present generation of European spaceborn SARs (ERS-1 and ERS-2) uses a fixed beam antenna with slotted waveguides as radiators and a centralized receiver and transmitter. The next generation SAR systems require dual polarized antennas with steerable beams. Distributed T/R modules will be used, where each module feeds a dual polarized subarray. The paper presents the electrical analysis and design of a large C-band microstrip advanced SAR antenna (ASAR) developed for the European Space Agency. The paper also presents a recently developed method for predicting co- and cross-polar radiation from microstrip array antennas including spurious radiation from the associated microstrip feed line network