Broadband and efficient reflective polarization converter based on a three-dimensional metamaterial

Abstract

In this paper, a three-dimensional metamaterial was proposed to realize a broadband and efficient polarization conversion. The unit cell of the three-dimensional metamaterial is composed of pseudo-planar structure and a ground plane separated by a dielectric spacer. The linear polarization of incident waves can be converted to its orthogonal direction upon reflection. The simulated results show that the polarization conversion ratio of more than 95 % is observed in the broad frequency range from 7.39 to 13.87 THz. The novel pseudo-planar reflective polarization converter can improve the magnitude of the polarization conversion ratio compared to previous works. To explain the mechanism of the proposed structure, the surface current distributions are investigated. In addition, the right-hand circularly polarized incident waves can also be converted to left-hand circularly polarized wave with broadband and efficient polarization conversion. The proposed metamaterial provides an alternative platform to promote potential applications in the terahertz region.