Single-Layer Frequency Selective Surface With Angular Stability Property

In this letter, a single-layer frequency selective surface (FSS) with high angular stability is proposed. By combining two modified cross loops, the proposed combined FSS (CFSS) element is obtained. Due to the rotationally symmetrical structure, the CFSS is insensitive to the TE or TM polarizations incidence. By the combination, the angular stability property is achieved that the maximum resonant frequency deviation is 0.08 GHz when the incident angle ranges from 0 degrees to 85 degrees. The mechanism of the CFSS is studied by both the equivalent circuit model and numerical analysis. A prototype is manufactured and measured in an anechoic chamber to verify the theoretical analysis. The simulated and measured results have good agreements, and all the performances are proved.