Subarray Design for Grating Lobe Suppression in Synthetic Aperture Interferometric Radiometers

In Synthetic Aperture Interferometric Radiometers (SAIRs), the large spacing between array elements leads to the appearance of grating lobes in the array factor (AF). To address the above limitation, this paper proposes a subarray antenna design method from the perspective of unit antenna optimization to suppress grating lobes. The subarray antenna is designed to adjust the zeros of the pattern to match the grating lobes of the AF, thus suppressing aliasing artifacts. Finally, the effectiveness of the proposed method is verified through simulations. The results demonstrate that the proposed method effectively suppresses aliasing artifacts in imaging results while maintaining system simplicity and computational efficiency, making it a practical solution for high-performance SAIR applications.