Bispectral camouflage metasurfaces compatible with microwave diffuse emission and tunable infrared emissivity

With the rapid development of detection technology and artificial intelligence, the widespread use of multispectral detectors has increased challenges to stealth capabilities. This paper presents a bispectral camouflage metasurface with microwave diffuse emission and tunable infrared (IR) emissivity, achieving an integrated design for radar cross-section (RCS) reduction and tunable IR emissivity. The structure consists of layers from bottom to top: aerogel felt, indium-tin-oxide (ITO), air, polyethylene terephthalate (PET), and ITO. It reduces RCS through microwave diffuse reflection and adjusts IR emissivity by controlling the ITO fill ratio. Both simulations and experiments demonstrate effective suppression of electromagnetic (EM) wave backscattering within 4.5–10.3 GHz, achieving radar invisibility. The tunable IR emissivity ranges from 0.2 to 0.7 with good thermal insulation. This design alleviates issues related to structural thickness and processing complexity and avoids increased thermal load from microwave absorption, offering better tunable IR emissivity for various thermal camouflage environments. This metasurface holds significant promise for multispectral stealth and IR camouflage applications.