**6. Conclusions**

A large-scale array antenna is one of the core components of high-performance spaceborne SAR, which determines the performance of spaceborne SAR to a great extent. The traditional spaceborne SAR phased array antenna adopts the periodic array implementation scheme, which has the advantages of strong beam control ability, sufficient failure redundancy backup, mature design method, and so on. It has been widely used in the existing spaceborne SAR system. However, the phased array antenna based on the periodic array scheme has the disadvantages of large size, heavy weight, high manufacturing cost, and low energy utilization, which restricts the further improvement of the performance of the spaceborne SAR system and the research and development of the next generation of high-performance spaceborne SAR system. Using aperiodic array antenna, parabolic array antenna and hypersurface array antenna have the possibility to overcome the above shortcomings. Based on the technical characteristics and development trend of spaceborne SAR array antenna, this article reviews the theoretical analysis, simulation results, and experimental verification.
