Ultra-wideband linear-polarization conversion metasurface with high-efficient asymmetric transmission

In this paper, we present an ultra-wideband linear-polarization converter with excellent efficient asymmetric transmission characteristics. Numerical simulations present that the polarization conversion ratio is greater than 0.9 at 4.6-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-$$\end{document}14.0 GHz and its asymmetric transmission parameter reaches 0.7 at the same frequency region. The microwave experiment is performed to prove the simulations, and the experimental results coincide with the simulation results. The mechanisms of polarization conversion and asymmetric transmission are explained by distributions of surface current and electric field. The superposition of multiple resonances broadens the bandwidth. We believe that our work is of great significance to potential applications for manipulating electromagnetic waves.