Preparation and microwave absorbing properties of carbon fibers/epoxy composites with grid structure

Microwave absorbing materials of carbon fibers/epoxy composites with grid structure are designed and fabricated based on the idea of gradient impedance. The microwave absorbing properties of the materials are measured by using a microwave network analyzer in the frequency range of 8–18 GHz. The results show that the as prepared composites behaving excellent microwave absorbing property. Compared with the carbon fibers/epoxy composites with monolayer grid structure, the composites with multilayer grid structure have better impedance matching and microwave absorbing property. Specially, the reflectivity value of the carbon fibers/epoxy composites with three-layer grid structure is less than −10 dB in the range of 10–18 GHz, showing broadband microwave absorbing properties. Carbon fibers/epoxy composites with grid structure are believed to be the ideal candidate of novel microwave absorbing materials with lightweight, wide-frequency and excellent microwave absorbing property.