A Polarization-Independent Frequency Selective Surface Based Switchable Absorber / Rasorber

This paper presents a frequency selective surface (FSS) based active design, which exhibits switchability between an absorber and a rasorber structure. Active components p-i-n diodes are symmetrically mounted in the geometry to realize the switching activity. For absorption, it adopts the concept of a circuit analog absorber during ON state, whereas for rasorber, an additional transmission window along with the broadband absorption is obtained during OFF state. The absorption band lies from 5.04 to 11.38 GHz for both the states, covering C and X bands in the spectrum, while the OFF-state transmission band is appearing at 2.82 GHz in the rasorber. Further, the proposed topology is four-fold symmetric and exhibits polarization-insensitive responses, unlike the earlier switchable rasorber structures. A possible realization of the proposed geometry, through establishment of the biasing network, has also been provided.