Composite metasurface merging frequency selective surface and coding sequences for electromagnetic transmission–diffusion

We proposed a composite strategy that integrates the mechanism of a frequency selective surface (FSS) and a coding metasurface to achieve low-frequency transmission and high-frequency diffusion, so called electromagnetic (EM) transmission–diffusion integration. A double-layered metasurface consisting of a bandpass FSS and one-bit chessboard coding metasurface is proposed and fabricated for the EM functionality of transmission–diffusion. The numerical and measured results are in good agreement indicating that high-efficiency transmission and diffusion can be simultaneously achieved in the frequency bands of 4.9–6.3 GHz and 10–35 GHz, respectively. Simultaneously, the application of the proposed structure on the curved surface is verified by simulation, and transmission–diffusion performance is also obtained. Encouragingly, the proposed metasurface provides a novel approach for obtaining a wideband transmission window and diffusion within a single metasurface, which may find potential applications in the fields of integrated EM systems and stealthy radomes. (paper)