Design of a broadband switchable frequency selective rasorber/absorber

Abstract

A switchable wideband frequency selective rasorber/absorber based on PIN diodes is achieved in this paper. When the PIN diodes are switched ON and OFF, the designed structure switches the working states between an absorber and a rasorber, respectively. The proposed structure consists of non-switchable lossy layer and switchable bandpass frequency selective surface (FSS), which are separated by an air interlayer. In the state of rasorber, the 1 dB transmission band is obtained in 3.87-4.95 GHz with the minimum insertion loss of 0.28 dB at 4.31GHz. The structure presents an absorption band from 1.48 GHz to 3.37GHz with absorptivity up to 80% in absorbing state. In addition, an equivalent circuit model (ECM) is established to comprehend the operating mechanism of the switchable structure. Therefore, the designed switchable rasorber can be applied in the field of the smart radome.