Two-layered wave absorber using short carbon fibers having broadband characteristics

In this paper, two-layered wave absorber using short carbon fibers is proposed. The absorber is composed of short carbon fibers, which is attached to polyester fibers on a surface of polystyrene foam, and a metal plate as a reflector. Absorption characteristics of the absorber with one-layer showed that matching frequencies could controlled by the thickness of spacer and the length of carbon fibers. Then the absorber with two-layer using different length of carbon fibers was investigated. From these results, we prospected that absorption characteristics of each length of fibers were working independently. Measured results of the optimized absorber showed that the bandwidth over 10 dB absorption is for 1.5 to 12.0 GHz.