High-temperature-resistant frequency selective metasurface with low-frequency diffusion and high-frequency transmission

This paper presents a high-temperature-resistant frequency selective metasurface with wide-band low-backward scattering at lower frequencies and wide-band efficient transmission at higher frequencies. The metasurface consists of three functional layers: lagging made of a low-loss insulation tile, a diffusive metasurface and a frequency-selective surface (FSS). The diffusion metasurface is comprised of various specially arranged square rings, where meander lines are integrated, ensuring transmission at higher frequencies. Seperated by a piece of honeycomb paper, a triple-layer coupled-resonator spatial filter FSS is placed below the diffusive metasurface. Based on the phase cancellation technique and dual-resonance transmission, a 10 dB reduction of radar cross section is achieved from 2.45 GHz to 11.55 GHz and a wide-band transmission lower than 1 dB is obtained in 17.33-19.08 GHz. In addition, a standard thermal test and subsequent electromagnetic test show that our sample maintains good performance after being heated at 500 degrees C for 5 s. This work opens a new route for designing frequency-selective metasurfaces with high temperature resistance.