Broadband Metamaterial Absorber With Temperature Scalability up to 1000 °C

In this study, a high-temperature-resistant broadband metamaterial absorber is designed, fabricated, and tested across a temperature range from room temperature to approximately <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1000~^{\circ }$ </tex-math></inline-formula>C. The absorber is designed based on a high-temperature resistive frequency selective surface (RFSS), with the top resonant structure and bottom reflector plate made from a conductive composite material consisting of indium tin oxide (ITO) and glass powder. An alumina ceramic sheet is used as the substrate. The sheet resistance of the dielectric layer can be adjusted by varying the proportion of ITO, and it gradually decreases with the increase in temperature while maintaining excellent chemical and thermal stability at temperatures up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1000~^{\circ }$ </tex-math></inline-formula>C. The designed metamaterial absorber achieves a peak absorption rate of up to 0.999, with an absorption band spanning from L- to U-bands, a relative bandwidth of 198.9%, and an absorption rate exceeding 90%. Moreover, the absorber exhibits strong polarization insensitivity and maintains stable absorption performance across a broad range of incident angles, highlighting its potential for thermal-resistant stealth technology and high-temperature radar-absorbing materials in extreme environments.