Analytically Co‐Designed Absorption‐Diffusion Coding Metasurface for RCS Reduction

This work proposes a novel and simple design method for an absorption‐diffusion metasurface, combining a coding diffusion‐type metasurface with an absorbing layer. The diffusion and absorption properties are obtained through an analytical co‐design methodology derived from a straightforward Smith chart‐based construction. The metasurface itself is entirely metallic and employs a broadband unit cell. Simulations demonstrate a 10 dB bistatic RCS reduction over a 39.1% relative bandwidth for a prototype operating at 22 GHz in the presence of an absorbing layer. The proposed approach provides a new design methodology that explicitly couples the design of an absorbing layer with a diffuse metasurface. Furthermore, this co‐design technique can be applied to any existing diffusion metasurface.