Broadband and polarization-insensitive microwave absorbing composite material with transmission performance based on indium tin oxide metamaterial

In order to meet the needs of light-weight and broadband electromagnetic absorbing material for microwave system, a kind of composite material based on indium tin oxide (ITO) film metamaterial was designed and fabricated. The composite material was formed by combining ITO film metamaterial with polymethacrylimide(PMI) foam. The matching design between ITO film metamaterial and PMI foam was carried out by designing the structural unit and adjusting the conductivity of ITO film. The fabrication method of ITO film metamaterial was studied. The electromagnetic characteristics of composite material were analyzed. The results show that the reflectivity of the composite material is less than − 8 dB at 8–18 GHz, and the transmissivity is more than − 1.5 dB at 1–2 GHz. The bandwidth with reflectivity less than − 10 dB reaches 8 GHz. The density of the composite material is 0.052 g/cm³. The composite material has the characteristics of light-weight, integration of broadband absorption and transmission, polarization-insensitive and wide-angle.