Dual-Band Wide-Angle Scanning Phased Array Composed of SIW-Cavity Backed Elements

In this communication, an aperiodic dual-band phased array with wide-angle scanning performance is presented. A substrate integrated waveguide cavity-backed antenna, which has wide beamwidths at 4.8 and 5.8 GHz, is used as the basic array element. The phased array contains eight subarrays with an equally spaced arrangement, and each subarray is arranged in a symmetric structure. Theoretical and optimization methods, in which the main beams of the subarray and the full array are coincident and the maximum sidelobe of the full array points to the null of the subarray, are proposed for sidelobe reduction. Based on the optimized results, the main beam of the phased array can scan from -75° to +75° at both the frequency bands, and the array supports the 3 dB beam coverage from -86° to +86° at the low-frequency band and from -82° to +82° at the high band, respectively. The phased array is simulated, fabricated, and measured. The measured results validate its wide-angle scanning performance.