Realization of broadband reflective polarization converter using asymmetric cross-shaped resonator

Abstract

Cross-shaped resonator (CSR) in metamaterial usually corresponds to adjust resonant characteristics. In this report, a simple and broadband reflective polarization converter is realized at GHz frequencies by breaking the symmetry of the CSR. The experimental results demonstrate that the polarization conversion ratio (PCR) over 0.8 is achieved from 8.3 GHz to 14.3 GHz for linearly polarized (LP) incident waves under normal incidence. The high polarization conversion efficiency can be sustained when the incident angle increases to 60 degrees. By taking advantage of surface current distribution and the interference theory, the physical mechanisms are elucidated in detail. Finally, the broadband polarization conversion can also be achieved by decreasing the geometrical parameters of the converter in the mid-infrared frequency range.