Optimization design of circular polarizer based on reflex metal grating

Scattering characteristics of reflex metal grating are analyzed according to mode-matching method and space Floquet mode theory. Rectangular metal gratings are designed and optimized. The optimized double U-shaped gratings’ bandwidth is three times that of the rectangular ones, and the power capacity is 15 times. The CST simulation results show that the axial ratio of the circular polarization devices is 1.07 at the center frequency of 94 GHz, and right-handed circular polarization is realized.