An Electronically Switchable Metasurface for Multifunctional Electromagnetic Applications

The present paper introduces a multifunctional, electronically switchable metasurface consisting of a passive resistive frequency selective surface absorber combined with an active metasurface, operating in the band 9-13 GHz. By selectively controlling the biasing state (OFF/ON) of the PIN diodes included in the active layer, the response of the overall structure can be dynamically switched from total reflection to absorption mode. The passive absorber, positioned beneath the active metasurface, provides a wideband absorption behavior during the AFSS transparent state. The novelty lies in the hybrid combination of a switchable active surface with a passive and resistive FSS into a single arrangement, resulting in multifunctional characteristics with an extremely reduced number of PIN diodes. By deriving the pin diode equivalent circuit model, accurate full-wave simulations have been carried out. Results confirm the structure's ability to dynamically switch from total reflection to a -10 dB absorptivity level ranging from 9 to 13 GHz, under incidence angles up to 30°. Therefore, the proposed design can represent an effective and robust solution to realize multifunctional structures, essential for regulating electromagnetic wave propagation in manifold applications, as intelligent surfaces and radar cross section camouflaging.