Composite Frequency Selective Structure With the Integrated Functionality of Transmission, Absorption, and Scattering

In this letter, we propose a scheme of metasurface-combined absorptive frequency selective structure (AFSS) providing low-frequency scattering, broadband transparent window, and high-frequency absorption. Composed of a coding metasurface and a composite AFSS, the proposed frequency selective structure is constructed in a 3-D configuration. The composite AFSS loads blade array plasmonics structure and exciting spoof surface plasmon polaritons on planar periodic resonators. Furthermore, the coding metasurface above the AFSS provides a phase gradient for scattering diffusion in low frequency. We fabricate a prototype as the verification of the proposed approach. The simulated and experimental demonstration manifests the feasibility with a copolarized transmission band from 8 to 13.5 GHz with 1 dB insertion loss and a less than −10 dB reflection ranges 1.5–3.2, 8–13.5, and 16–22 GHz.