Low Infrared Emission Hybrid Frequency Selective Surface with Low-Frequency Transmission and High-Frequency Low Reflection in Microwave Region

摘要

In this essay, we put forward a mixed structure with the properties of low emission at infrared region and scattering-transmission integrated at microwave region. This hybrid structure is mainly consisted of three portions: a frequency selective surface (FSS), a checkerboard metasurface and a metal patches layer. The FSS displays low-pass and high-stop characteristic, which bounces microwaves at higher frequencies and enables microwaves to be transmitted at lower frequencies. The checkerboard metasurface, with reflective substrate, can minimize reflection at higher frequencies by the method of scattering elimination. Owing to the high-stop properties of the FSS and the it serves as the reflective substrate, the combination of FSS and metasurface can realize broadband reflection reduction at high frequencies. At the same time, the transmission window of FSS in low frequencies can be maintained. At infrared region, the metal patches layer on the top produces the high reflectivity, which makes the whole structure to achieve low infrared emission. Meanwhile, the metal patches layer as the superstrate is transparent for the microwaves, which provides conditions for the radar-infrared compatible design. Simulation results indicate that the value of the reflection reduction is above -10 dB in the frequency range of 6.8-11.6 GHz as well as the transmission band appears around 4 GHz. At the same time, the whole hybrid structure's emissivity is less than 0.3 in the infrared region. Finally, the experimental measurement is carried out and a good demonstration is supplied. We hope that our proposed structure can seek out a potential applications of multispectral stealth radomes.