Dual-broadband high-efficiency polarization conversion metasurface based on asymmetric transmission

A dual-broadband and high-efficiency polarization conversion metasurface based on asymmetric transmission is proposed, which is composed of two orthogonal metal gratings, metal resonator and FR-4 dielectric spacer. The simulated results show that the designed metasurface can convert x-polarized incident waves into y-polarized waves in the frequency ranges of 4.64–14.37 GHz and 17.02–37.23 GHz, and the corresponding polarization conversion ratio (PCR) exceeds 90%. The relative bandwidths of the two bands are 102.37% and 74.51%, respectively. The influence of structural parameters on the transmissive polarization conversion performance is studied. The bandwidths of the two bands can be easily modulated by varying the structural parameters of l, n, m and w. The excellent performance of dual-broadband and high-efficiency covers C, X, Ku, K and Ka bands, which can also be well maintained in the oblique incidence range of 0°–50°. Moreover, the mechanism of transmissive polarization conversion is analyzed. The prototype is fabricated and the experimental results are basically consistent with the numerical simulation. The proposed metasurface has potential application value in polarization imaging radar or radiometer, radar, transmission array antennas and filter.