Research on grating lobe suppression based on the virtual array transformation algorithm

In beamforming, the grating lobe is produced when the element spacing is increased to more than 1/2 wavelength. This paper outlines the mechanism of producing grating lobe and summarizes the used technologies of grating lobe suppression. Considering the issue of grating lobe suppression, this paper analyses the feasibility of ambiguity solving with virtual elements using the virtual array transformation algorithm and the virtual array algorithm based on least squares estimator. We use the least squares algorithm to estimate the received data of virtual elements between the adjacent elements based on the known received data of actual elements, and to reduce the spacing which can be set as 1/2 wavelength without change the actual aperture of antenna array, thus the grating lobes is suppressed. Simulation results verify the feasibility of the algorithm.