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.