A multiband transmittive-type linear-to-circular polarization converter

This paper discusses a transmittive-type multi-band linear-to-circular polarization converter based on a bilayer double-L-shaped metallic metasurfaces at microwave frequencies. The unit cell of the metasurface structure comprises with two L-shaped copper layers with different dimensions engraved on the two sides of a lossy FR-4 substrate of 1.6 mm thickness. The structure has been simulated employing the periodic boundary conditions. The proposed structure offers linear-to-circular polarization conversion of the incident electromagnetic wave at five distinct frequency bands covering X and Ku bands.