A broadband multifunctional switchable metamaterial for radar-infrared compatible stealth

This paper presents a switchable metamaterial based on a structured aqueous medium, which is an absorber/ reflector combining broadband switching capability and optical transparency. The proposed structure comprises an infrared shield layer (IRSL) and water-based radar switchable layers (WRSL). The significant switchable function between wideband absorptive states (12.44-28.72 GHz) and wideband reflective states (10-30 GHz) can be implemented by injecting and discharging purified water at normal incidence. Low infrared emissivity in the range of 3 similar to 14 mu m can be obtained by appropriately adjusting the filling ratio of the ITO film and pure water temperature. It is important to note that the broadband switchable characteristic of the proposed structure is still applicable at large incidence angles. The distribution of physical field and parametric analyses are presented to better understand the working mechanisms of water-based absorbers/reflectors from a specialized perspective. Finally, a prototype of the designed structure is also produced and validation tests are performed. The proposed metamaterial structures have excellent properties in the microwave, infrared and optical fields, which are expected to have important application prospects in electromagnetic modulation, multispectral stealth, electromagnetic compatibility and wireless communications.