Equivalent circuit model for analysis of frequency selective surfaces with ring and double concentric ring apertures

Abstract

In this study, the authors present two new proposals for representation by the equivalent circuit model for aperture-type circular ring geometries, not yet studied in the literature. The study consists of the frequency response representation of frequency selective surfaces (FSSs) formed by circular ring aperture and concentric circular ring apertures. At first, the authors performed an equivalent circuit analysis for a single cell formed by a single circular ring. Then, they extend the analysis to concentric circular rings, which when used as FSS unit elements, present two passband responses. They compare results of the proposed method with results obtained with the commercial software ANSYS HFSS, showing a good agreement between the results. They built four prototypes and compared measured results with simulated results obtained with the suggested method and it completes the proposed equivalent circuit validation.