Dual-wideband Cross Polarization Conversion Metasurface Based on a Symmetric Split Ring Resonator

Abstract

Polarization conversion metasurface has been widely studied from microwave to optical spectrum and utilized for many practical applications. In this paper, a dual-band and high-efficiency cross polarization conversion metasurface is proposed and investigated. Cross polarization metasurface unit is based on a perforated symmetric circular double split ring resonator which is deposited on a dielectric backed by a metal sheet. The proposed dual-band cross polarization metasurface can efficiently convert linearly polarized incident wave to its cross reflection direction with a 3 dB spectrum at Ku band (11.85 GHz ~ 18.42 GHz) and K band (20.76 GHz ~ 21.34 GHz) according to the optimized numerical simulation results based on finite integration method, respectively. The cross polarization conversion fractional bandwidth of the first reflective spectrum is above 50% while the second reflective spectrum is relatively narrowband. Besides, the proposed metasurface structure is insensitive to the polarization of the incident wave. The cross polarization conversion response to large oblique incident angle is also examined and investigated. It is shown that the proposed cross polarization conversion metasurface structure is insensitive to incident angle and its cross polarization conversion performance keeps almost constant even with 60° large oblique incident angle. The fabricated sample is in progress and the measured results will be compared with simulated results later. The proposed studies on the perforated symmetric circular double split ring can find many potential applications in polarization-controlled devices which possess relative broad bandwidth, high-efficiency, insensitive to polarized direction and oblique angle of incident wave.