Dual-band metasurface for broadband asymmetric transmission with high efficiency

Abstract

In this paper, a dual-band asymmetric transmission metasurface for linearly polarized wave is designed, analyzed, and verified experimentally for operation in S- and C-bands. The metasurface is established by a bi-anisotropy structure with three metallic layers separated by dielectric spacers. Symmetric rectangular split-ring resonators are adopted in the top and bottom metallic layers while modified metal strip with stepped widths is utilized in the middle. Both asymmetric transmission capability and operation bandwidth are remarkably improved. According to simulation, the design yields an asymmetric transmission parameter above 0.8 within two operation bands: 2.53-2.56 and 3.80-4.71 GHz, fractional bandwidths of 1.18% and 21.39% can be deduced, respectively. The oblique incidence property is further analyzed, which demonstrates robustness response to incidence up to 50°. Two operation bands, 2.53-2.56 and 3.87-4.78 GHz, are also validated through measurement. The corresponding bandwidths 1.18% and 21.04% show tiny discrepancy related to simulated results, which validate the reliability of the design. Comparisons with other recent published results show that this structure provides relative low profile, wider operation band with high asymmetric transmission efficiency. The proposed metasurface could be applied for electromagnetic interference suppression and polarization control for modern radar and satellite communication systems and can be scaled to operate for higher frequencies with considerable bandwidth and efficiency.