A FSS-Based Polarization Insensitive Switchable Rasorber/Absorber

In this article, a novel dual polarization switchable rasorber/absorber is presented. The proposed structure consist of a resistive lossy layer and an active bandpass FSS layer separated by an air spacer. When the PIN diodes are in OFF state, the proposed structure behave like a "rasorber" whereas this nature completely changes into an "absorber" state when the diodes are made switched ON by applying suitable bias voltage. The novelty of the proposed rasorber lies in its symmetric configuration which makes the structure polarization insensitive unlike the earlier reported switchable designs. Moreover, insertion loss (IL) in rasorber mode is found to be extremely small whereas absorption bandwidth at other mode is sufficiently large; both intensely justify its applicability in realistic scenario. Additionally, a simplified bias network is also adopted to feed the semiconductor device which neither requires any complicated biasing grid nor requires any additional layer. Further, a sample prototype is also fabricated and experimentally measured where a good agreement with simulated results is obtained.