Low-profile reflective polarization conversion metasurface with frequency selective characteristics

We proposed a low-profile reflective polarization converter based on anisotropic metasurfaces. By properly designing the unit cell structure, the proposed metasurface can achieve frequency selective polarization conversion. When the proposed metasurface is illuminated by a linear polarization incoming wave, the circular polarization outgoing waves are implemented in frequency-band-1 (6.87 to 16.83 GHz) and frequency-band-2 (19.72 to 23.64 GHz), but the rotation direction of the circularly polarized reflections are orthogonal over the two bands. In addition, cross polarization conversion is achieved in frequency-band-3 (17.38 to 18.6 GHz). Indeed, the proposed metasurface can also serve as a circular to linear polarization converter. The theoretical analysis and the physical mechanism are given to understand the polarization conversion phenomenon. The measured result is consistent with the simulation. The proposed metasurface can be utilized in the design of a circularly polarized reflectarray with linearly polarized feeding.