Radar Absorbing Properties of Light Radar Absorbing Materials Based on Hollowa2porous Carbon Fibers

A kind of lightweight and wideband radar absorbing materials were prepared based on resistance matching principles and electromagnetic wave propagation laws. These materials consist of two-layers, one made of PAN-derived hollowa2porous carbon fibers contributing to the low density, and the other made of carbon blacks, short carbon fibers or carbonyl iron powders acting as the matching layer. Their radar absorbing properties investigated show that the introduction of the matching layer, as well as the properties of the matching layer, plays an important role in improving the absorbing properties of the materials. Carbonyl iron powders are more suitable for the matching layer than the other two as the radar absorbing properties concerned. Thus obtained material has a bandwidth of 11.42GHz under -8dB, and a bandwidth of 10.90GHz under -10dB in the range of 4-18GHz, provided that the thickness and the density are 2.90mm and 1.28g/cm3, respectively.