Reconfigurable Metasurface with Multiple Functionalities of Frequency-Selective Rasorber, Frequency-Selective Surface, Absorber, and Reflector

Multi-functional metasurfaces have shown great promise in tackling complex electromagnetic issues. Reconfigurable frequency-selective Rasorbers (FSRs) have recently received growing attraction, but existing designs are constrained in their switchable modes, typically limited to FSR/Absorber or FSR/frequency-selective surface (FSS). To address this limitation, a new metasurface that integrates four different functioning modes, including FSR, FSS, Absorber, and Reflector is proposed, which can be dynamically switched as demanded. The design is based on the theoretical network model analysis, and its intriguing performances are verified through simulations and experiments both in frequency and time domains. The results show that the FSR and Absorber modes exhibit wide low-scattering bandwidths with narrow transmission windows that can be turned on or off. These two modes also eliminate the sputtering effect, making it suitable for stealth applications. In contrast, the Reflector mode is efficient in blocking microwaves across a broad spectrum, and a transmission window can be opened in the FSS mode. It is believed this multi-functional metasurface can serve as a radome to protect against various challenges such as detection, interference, and high-power invasion.