Investigation on the electromagnetic parameters of organic conductive fibers and carbon fibers

Electromagnetic parameters in X band of composites comprising epoxy and one of the 2 types of organic conductive fibers or 3 types of polyacrylonitrile-based carbon fibers were investigated in this paper. Volume fraction of different fibers in these composites was 3.5%, Electromagnetic parameters of the fibers were comparatively investigated on the basis of the functional relationship of the equivalent electromagnetic parameters of the composite with the electromagnetic parameters of the components in the composite, the Volume fractions of the components in the composite and with the working frequency. The results indicated that all the fibers we investigated were dielectric lossy materials, and the magnetic loss by these fibers in X band was negligible. Dielectric loss tangents of organic conductive fibers were not high enough for anti-radar camouflage application owing to the limited amount of conductive agents in the fiber. Dielectric loss tangents of carbon fibers were much higher than those of organic conductive fibers and were related to the carbonization temperature. Too high and too low carbonization temperatures were both unfavorable for the increase of dielectric loss capability of carbon fibers.