A design of ultra-wideband linear cross-polarization conversion metasurface with high efficiency and ultra-thin thickness

In this work, a polarization conversion metasurface is proposed, which can convert linearly polarized electromagnetic (EM) waves into cross-polarized waves in ultra-wideband at high polarization conversion efficiency. The proposed sandwiched metasurface, composed of a top anisotropic resonator structure, an intermediate dielectric substrate, and a bottom metallic ground, has an extremely thin thickness (only 6.6% of the longest wavelength of the working frequency range). Both numerical simulation and experimental results illustrate that the metasurface can work in the ultra-wideband (ranging from 9.04 to 20.83 GHz) with a high polarization conversion ratio (>0.9). Polarization conversion in a wide bandwidth is attributed to multiple resonances in the operating frequency range. Additionally, the proposed metasurface also shows good performance for oblique incidence. It is expected that the designed metasurface will be more convenient for integration within ultra-thin EM devices.