Filtering and Wide-Angle Scanning Phased Array Based on Optimized Subarray With Flat-Top Gain Curve

Abstract

This study presents an optimization-based approach for designing wide-angle scanning phased arrays with filtering response by synthesizing subarrays with a broadside flat-top gain curve. A dual-layer parasitic pixel surface is loaded above a four-element source subarray to provide a high degree of synthesis flexibility. Assisted by the internal multiport method-based optimization, the flat-top gain curve of the whole subarray and the heterogeneous radiation patterns of the subarray elements can both be efficiently realized under a specific pixel surface configuration. Afterward, the subarray is extended into an eight-element wide-angle scanning phased array. Simulated and measured results demonstrate that the final array can achieve the wide-angle scan from −60° to +60° within a broad active impedance band 5.0–5.9 GHz (16.5%). Besides, when the proposed phased array scans in the wide-angle range, it exhibits a good filtering response with dual radiation nulls and out-of-band suppression levels of up to 10 dB.