A design project of multifunctional broadband electromagnetic-wave-absorbing carbon fiber fabric composite by regulating periodic structure

Long continuous carbon fiber (LCCF) exhibits strong electromagnetic attenuation performance and excellent mechanical strength. However, its impedance matching is often inadequate, preventing broadband effective absorption. Herein, a carbon fiber fabric (CFF) and epoxy resin composite with a periodic structure is developed, which offers enhanced electromagnetic wave absorption and improved bending strength, based on the optimization of the arch cavity height. We investigated the relationship between the design parameters of the periodic structure and the absorption performance through a combination of simulations and experimental feedback. Our results suggest that the gradient impedance induced by the arch cavity in the CFF composite significantly improves impedance matching, leading to broadband effective absorption (RL <-10 dB) over the frequency range of 3.4 similar to 18 GHz (14.6 GHz). Furthermore, the CFF composite demonstrates a stable frequency response for incident angle between 5 degrees and 45 degrees under both TE and TM polarization. Notably, the composite achieves a maximum bending strength of 110.5 MPa. This composite, with its combination of broadband effective absorption and mechanical properties, holds significant potential for electromagnetic protection applications.