Broadband polarization-insensitive microwave-absorbing composite material based on carbon nanotube film metamaterial and ferrite

To meet the requirements of efficient broadband microwave-absorbing materials for a variety of technological equipment, a composite material based on a carbon nanotube (CNT) film metamaterial and ferrite is designed and fabricated in this study. To this end, available methods for the design and fabrication of the CNT film metamaterial are examined, and the optimal design of the CNT film metamaterial and a ferrite absorber is proposed. The broadband microwave-absorbing composite material was prepared by combining the CNT film with the ferrite absorber according to the design, and the microwave-absorbing properties of the composite material were studied. The results of experiments show that the reflectivity of the composite material was lower than -8dB at 4-18GHz at a bandwidth of 14GHz, which is significantly better than the reflectivity obtained using a single ferrite absorber. Moreover, the composite material is insensitive to electromagnetic wave polarization.