Zhibo Huang, Sijia Li, Zhe Cheng, Yuhao Wu, Xinkun Ma, Ming Liu, Yulong Zhou
Traditional microwave absorbers with limitations of narrow band absorption, single functionality, and difficulty in conforming to complex surfaces are no longer sufficient to meet the demands of modern equipment for multispectral stealth. This paper proposes a flexible optically transparent metasurface (FOTMS) with simultaneously ultra-broadband millimeter-wave absorption and infrared (IR) stealth. Tri-layer indium tin oxide (ITO) patterned layers were designed and etched onto flexible transparent polyethylene terephthalate (PET) substrate, achieving radar-IR bi-stealth, optical transparency and a flexible configuration. Both simulated and experimental results indicate that the metasurface features absorptivity more than 90% within 15–38.7 GHz, while exhibits 10 dB radar cross section (RCS) reduction for curved configurations. Additionally, the metasurface displays polarization insensitivity and stability at different incidences and polarization angles. Meanwhile, the entire structure maintains a high optical transmittance of 85.09%, and the average infrared emissivity of metasurface is 0.47 for 3–14 μm. This work provides an effective strategy for optical windows and multispectral stealth.