Absorptive frequency selective surface with two alternately switchable transmission/reflection bands.

The traditional frequency selective surface (FSS) needs further improvement with the development of stealth technology, and the design of multifunctional FSSs is essential. In this letter, an active absorptive FSS (AFSS) has been designed based on the absorption structure of the spoof surface plasmon polariton (SSPP) and the switching activity of the active FSS. The active FSS embedded with PIN diodes realizes the shift of two transmission/reflection frequency bands by controlling the bias voltage of the feed network, which switches from one band-pass response (at around 3.06 GHz) to the other (at around 4.34 GHz). And when one of the transmission windows switches to the other, the original transmission window closes. The upper plasmonic structure achieves a continuous and efficient absorption band from 6.31 to 8.34 GHz. A sample was also fabricated and carried out to verify the numerical simulation, and the experimental and simulation results are consistent. This work provides new ideas for the design of active AFSS and promotes its application in common aperture radome, antenna isolation, and electromagnetic shielding.