Broadband reflection of polarization conversion by 90° in metamaterial

We developed a reflection polarization convertor by using the conventional metamaterial absorber. The metal-dielectric-metal sandwich structure, in which copper split ring at the front and metallic plane at the back are separated by FR-4, was employed to investigate for the GHz regime. This shows that a broadband of 14–18 GHz with reflectance of 36–55% is converted to 90°-polarization mode, while the original one is nearly harvested (absorption of 95–100%). In other words, the original electromagnetic (EM) wave is “perfectly” absorbed and partly emitted as 90°-twisted EM wave, and the remaining is dissipated as heat.