Broadband metamaterial absorber with thermal insensitivity up to 600 °C

• Published in: Applied physics. A, Materials science & processing Vol. 127; no. 9
• Main Authors: Qiao, Jian, Liu, Yufu
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2021; Springer Nature B.V
• Subjects: Absorbers; Absorbers (materials); Absorption; Aluminum; Applied physics; Arrays; Broadband; Characterization and Evaluation of Materials; Condensed Matter Physics; Electrical resistivity; Frequency ranges; Frequency selective surfaces; High temperature; Machines; Manufacturing; Materials science; Metamaterials; Molybdenum disilicides; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Reflectance; Room temperature; Surfaces and Interfaces; Thin Films; Metamaterial absorber; Thermal insensitivity; Resistive frequency selective surfaces; Broadband absorption; Electrical conductivity
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-021-04863-5

A broadband metamaterial absorber on the basis of a single square-loop resistive frequency selective surface (RFSS) with scalable high-temperature absorption was numerically simulated, fabricated, and measured in the frequency range of 7 to 13 GHz. The RFSS arrays, with an effective sheet resistance of approximately 40 Ω/sq at room temperature, were made from a mixture of MoSi 2 powder, Al powder, and water glass with a mass ratio of 11:1:5 (Al content of 11.51 vol%). The sheet resistance of the RFSS arrays was found to decrease from approximately 500 Ω/sq to 3 Ω/sq with an increase in Al powder content to 31.93 vol% and the temperature coefficient of electrical resistivity was shown to be positive experimentally. The experimental results show that the reflection coefficient was less than −  10 dB from near 7 to 11 GHz from room temperature to approximately 600 °C, resulting in a broadband absorption over 90% with thermal insensitivity. They agreed with the simulation results reasonably well subject to small uncertainty in the sheet resistance.