A High-Temperature-Resistant Frequency Selective Rasorber with Low-Frequency Diffusion and High-Frequency Transmission

A frequency selective rasober (FSR) with high-temperature-resistance, wideband radar cross section reduction (RCSR), and flat-broad transmission band is presented in this paper. It consists of three functional layers: a piece of insulation tile, scattering cancellation metasurface based on interdigitated element, and a triple-layer-coupled-resonator spatial filter frequency selective surface. At low-frequency band, the incident energy is diffused to various directions, resulting in 10 dB RCSR over 2.52-11.68 GHz with a 129% fractional bandwidth. Besides, there is a highly efficient transmission band (insertion loss < 0.595 dB) over 16.53-19.83 GHz. It is also worth mentioning that our FSR can maintain such good properties at 500°C for 5 seconds with the help of insulation tile.