Optically transparent metasurface Salisbury screen with wideband microwave absorption

We present an optically transparent broadband microwave absorber based on the concept of metasurface Salisbury screen (MSS). The metasurface with optimized reflection phase profiles is used as the ground plane to excite multi-MSS resonances that are required for achieving continuous wide absorption bandwidth. Meanwhile, by employing indium tin oxide (ITO) film and glass dielectric substrate, high optical transparency and wideband microwave absorption can be obtained simultaneously. Both full-wave electromagnetic simulations and experiments demonstrate that the transparent MSS can perform an efficient absorption over 89% in an ultra-wide frequency band ranging from 4.1 GHz to 17.5 GHz with a sub-wavelength thickness. In addition, good angular performances are observed for all wave polarizations. The proposed MSS may provide a powerful platform for efficiently designing broadband absorption in microwave region with advantages of light weight, thin thickness, and high optical transparency, which could further find potential uses in many real-world applications. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement