Microwave absorption properties of carbon fibre containing nonwovens

Abstract

A variety of nonwoven containing different weight percentages of pitch-based carbon fibre has been developed using through-air thermal bonding process or the spray bonding process and studied for its microwave absorbing capacity in the microwave frequency range 8 - 18GHz. Microwave reflectivity of the nonwoven is found closely related to the carbon fibre content. Electromagnetic parameters of the component fibres in the nonwoven have also been studied. Variation in microwave absorbing capacity of the nonwoven with the carbon fibre content is expounded according to the relationship between the electromagnetic parameters and the reflection coefficient of the nonwoven, as well as the relationship between the electromagnetic parameters and the attenuation constant of the nonwoven. The carbon fibre containing nonwoven has great potential in the military application as the radar camouflage material or in the non-defense application as the electromagnetic shielding material.