Grating Lobe Suppression in Wide-Angle Scanning Phased Array with Large Inter Element Spacing by Subarray Rotation

Abstract

The use of mmWave and THz is required in wireless communication according to the advantages of broadband use. The scanning range of the phased array is limited by grating lobes caused by the antenna elements' interval increase. Antenna element intervals where grating lobes do not occur are physically small according to high frequencies, so it is small compared to chip size and difficult to manufacture. The grating lobe was reduced by arranging a subarray composed of 4 × 4 antenna elements having an interval of 1λ0. By reducing the grating lobe by giving spacing between subarrays and rotating the subarrays, the sidelobe level is as low as-10dB or less. The proposed phased array antenna arrangement has a large interval between antenna elements and does not overlap between subarrays, so it is easy to manufacture and achieves a low sidelobe level even during steering.