Simultaneous Optimization of Subarray Weights and Sizes for Low Sidelobe Synthesis of Large Array Antennas

Large array antennas of wide dimension are often used in several communication and radar systems. Thanks to their performance (e.g., the patterns are electronically steerable, the illumination can be controlled directly on the aperture, etc.), array antennas have replaced parabolic reflectors in many challenging and real applications. Nevertheless, large phased arrays still represent too expensive solutions because of the large number of radiating elements and the high circuit complexity. For this reason, the subarraying strategy has been widely adopted in order to simplify the antenna design and to achieve a better trafe‐off between cost and performances. Accordingly, the elements on the array aperture are grouped into clusters and a gain is assigned to each of them. Since the use of amplitude weights at the output of the subarrays generates unavoidable grating lobes [1], various strategies have been proposed to synthesize subarrayed antennas with low sidelobe levels (s) [2]‐[4].