High temperature insensitive ultra-thin electromagnetic metasurface based on ytterbium monosilicate ceramic coating

Abstract In this article, homogeneous multi-functional materials and artificially design method are proposed to design ultra-thin metasurfaces, which broaden the application over a wide range of temperatures due to their excellent mechanically-thermally stable structure and electromagnetic functional performance. Ideal environmental barrier coating material of ytterbium monosilicate (Yb2SiO5) possesses stable dielectric property over a wide temperature and frequency range. As a thermal corrosion resistant coating, NiCrAlY possesses excellent conductivity at high temperatures. These two materials are selected as substrate and conductive units to composite temperature insensitive ultra-thin refractory metasurface coating (RMC) for wideband radar cross section (RCS) reduction. Three types of RMC patterns are discussed, namely chessboard, staggered, and random. The prototype of staggered pattern was prepared using atmospheric plasma spraying (APS) technique. Both the simulated and experimental results indicated that RCS is reduced remarkably in a wideband frequency, as well as demonstrated stable reduction performance over a broad range of temperatures. Along with a protective layer of Yb2SiO5, only a thickness of 1.4 mm is required. The protective layer is employed to isolate the contact between the structural layer and the outside environment, which can significantly increase the service life of the metasurface. This work brings bright prospects for various kind of metasurfaces in practical high temperature applications and significantly enriches the research of metasurfaces.