Design and Characterization of a High-Temperature Resistant Thermal Infrared Stealth Film with Radiative Cooling and Broadband Radar Transparency

Infrared stealth for high-temperature targets is of considerable significance. Multilayer-film-based selective thermal emitters can effectively regulate thermal radiation, thereby offering a promising solution to stealth challenges. In this work, a novel selective thermal emitter based on a multilayer thin film is designed. The film consists of ten layers constructed from five materials: TiO2, Al2O3, HfO2, Ge, and SiO2. Experimental measurements show that, at room temperature, the multilayer film exhibits an emissivity of 0.199 in the mid-infrared band and 0.219 in the long-wave infrared band, demonstrating excellent infrared stealth performance. In the non-detection band (5–8 µm), an emissivity of 0.774 is achieved, enabling effective heat dissipation. At elevated temperatures up to 500 °C, the multilayer film still maintains favorable infrared stealth and radiative cooling performance. Furthermore, experiments demonstrate that the film possesses outstanding radar-wave transparency in the 2–18 GHz band, making it suitable for subsequent integration with radar-absorbing materials to form composite structures and achieve compatible stealth. The designed and fabricated multilayer film provides a new reference for the realization of high-temperature-resistant selective thermal emitters.