Higher Performance Honeycomb Sandwich Metamaterial Microwave Absorber Based on Porous Carbon Combined with Ferroferric Oxide

The sandwich metamaterial based on "honeycomb-like" porous carbon combined ferroferric oxide (Fe3O4) was reported in this paper. By manipulation of the content of carbon and Fe3O4 for adjusting complex and permittivity and permeability, the as-prepared composite P–C-800@Fe3O4 unit cells were used to optimize the electromagnetic composite metamaterials for broadband absorption. For the normal incidence of electromagnetic waves, the sandwich metamaterials demonstrated an excellent broadband absorption in the frequency range of 5–18 GHz and achieved high absorption at low frequency. Meanwhile, the metamaterial structure also can display a wide-angle absorption performance from 0 to 45° for transverse electric (TE) and 0 to 75° for transverse mangentic (TM) mode. The results could contribute potentially to the development of metamaterial absorber applications based on traditional materials, and this research will provide an effective method of lightweight broadband and wide-angle microwave metamaterials for engineering applications in the future.