Polarization-Insensitive Switchable Frequency-Selective Rasorber/Absorber

In this paper, a switchable frequency-selective rasorber/absorber structure has been presented based on the reconfigurable characteristic of p-i-n diodes. The proposed design comprises a top resistive layer and a bottom switchable layer, separated by an air spacer. P-i-n diodes are symmetrically mounted across the slots in the bottom topology such that the overall geometry exhibits a switching operation between a low-profile broadband absorber and a rasorber (broadband absorber with narrow transmission band), with the control of the biasing state. An equivalent circuit model has been presented to investigate the operating mechanism of the geometry. Further, the proposed design is polarization-insensitive and angularly stable.