Broadband flexible metamaterial absorber using Carbon fiber loaded silicone foam

In this paper, we propose a new and original absorbing material based on silicone foam loaded with long carbon fibers (12 mm). This flexible composite is structured in a periodic way, like "metamaterials". The originality of the proposed absorbing material resides, on the one hand, in the association of two simple fabrication concepts (a simple production of the silicone foam and a simple periodic structuring of this foam) and, on the other hand, in the use of dielectric lossy material to make periodic broadband absorbing structures. The idea here is to replace standard metamaterial absorbers, based on structured metallic film (often copper) deposited on a dielectric substrate, by organic metamaterial. Thus, a flexible absorber of 16 mm thickness, with the shape of a "chessboard" and having a broadband absorption bandwidth with the reflectivity below −10 dB in the frequency range of 4-18 GHz is proposed and implemented. Moreover, we also obtain a good absorption response by varying the incident angle up to 30°.