Realizing ultra-bandwidth cross-polarization conversion by a double-layer metasurface

In this paper, a double-layer structure of ultra-bandwidth cross-polarization converter (PC) has been devised in line with the rationale of the metasurface. The project can bring about a superior 90 degrees conversion effect of the incident wave when it is perpendicularly incident. This PC is an improvement and majorization of the single-layer PC with a bowknot surface structure, which can hit the mark of improving the polarization conversion ratio in the low frequencies and enlarging the bandwidth. In this article, not only is the basic principle of polarization conversion examined but also the parameters are discussed. In addition, points of view such as incidence angle and current are utilized for analysis. Ultimately, the cross-polarization conversion can be achieved in the range of 0.63-1.50 THz, whose relative bandwidth is 81.7% and bandwidth is 0.87 THz. The proposed design may be worth applying in radar, communication, and imaging technologies. (C) 2020 Optical Society of America