Reconfigurable Frequency Selective Surface Switching between Absorption and Transmission Band

Abstract

A polarization-insensitive reconfigurable frequency selective surface (RFSS) using p-i-n diodes is presented in this paper. The proposed structure consists of periodically arranged metallic patterns printed on the two sides of an FR4 dielectric substrate on which the p-i-n diodes are mounted in the bottom surface. Based on the biasing conditions of the diodes, the geometry acts as a radar absorber and a bandpass filter under different states. The simulated response exhibits a near unity absorption response (having absorptivity of 92.44%) at 7.08 GHz during ON state of the diode, whereas the incident electromagnetic wave gets transmitted through the structure at 5.64 GHz during OFF state. An embedded biasing circuitry has also been developed comprising of metallic vias and inductors, such that the overall topology remains four-fold symmetric and displays polarization-insensitive responses for both the states. The structure has been studied with the help of a circuit model and other parametric variations to explain the switching mechanism under different biasing conditions. Such RFSS can be considered as a potential candidate for various radome applications. © 2022 IEEE.