Grating Lobe Cancellation Mechanism and Control Strategy for Large-Spacing Arrays Based on Null Multiplication Method

Large-spacing phased arrays offer significant advantages in reducing system cost, energy consumption and complexity, but their application is severely limited by inherent grating lobes during wide-angle scanning. To overcome this critical limitation, this paper introduces a novel "null multiplication" mechanism for grating lobe cancellation. The core principle involves partitioning the array into subarrays composed of null-reconfigurable antenna elements. It then systematically leverages the synergistic product of the nulls from the subarray factor and the element pattern to create a composite null. This synthesized null is sufficiently wide and can be dynamically steered to precisely track and suppress the grating lobes. A practical 2D null-reconfigurable element is designed to validate the concept. Simulation results demonstrate that for arrays with element spacing up to 2.0λ, the method achieves effective suppression within a wide ±75° scanning range, confirming its high efficiency and practicality.