Stacked tunable metasurface achieving sharp frequency filtering with polarization and spectral reconfigurability

Abstract Increasingly complex electromagnetic environments and congested spectral resources demand the crucial frequency-selective filtering to suppress out-of-band interference during wave manipulation. Here, we present a stacked reconfigurable metasurface that achieves sharp frequency filtering together with multidimensional tunability across polarization and spectral domains. This stacking strategy decouples polarization channels and tailors near-field coupling to realize controllable frequency shifts. A transmission-line theory is analytically established to characterize and control the scattering poles and zeros under varying polarizations and bias voltages, thereby enabling the prediction of the metasurface’s tunable filtering behavior. Experiments validate dynamic polarization selection and continuous shifting of the filtering band. The measured bandpass response exhibits steep transition edges and strong out-of-band rejection, effectively isolating adjacent spectral channels. This design demonstrates the integration of tunability and selectivity across multiple wave dimensions, addressing critical demands for reconfigurability, multiplexing, and interference immunity in modern electromagnetic systems, with broad potential for smart sensing, secure communications, and radar technologies.