Double layered radar absorbing structures of Silicon Carbide fibers/polyimide composites

High performance radar absorbing structures were fabricated using polyimide as matrix, Silicon Carbide fibers (SiCf) as reinforcement, and the effect of carbon-based absorbent (carbon nanotubes (CNTs) and graphene nanoplatelets (GNP)) content on the mechanical and electromagnetic absorbing properties was studied and analyzed. The results indicated that the complex permittivity increased with increasing the filler content due to the high polarization ability, while the flexural strength of the composites decreased owing to the poor dispersion properties. The absorbing properties of carbon filler-SiCf/polyimide composites can be adjusted by the kinds of absorbent, the content and the thickness. In order to enhance the absorbing bandwidths, double layered structures were designed and simulated, and the minimum reflection value can reach to -29.8dB. This material can be using as a kind of high performance radar absorbing structures.