Efficient dual-band asymmetric transmission of linearly polarized wave using a chiral metamaterial

In this paper, a three-layered chiral metamaterial composed of three twisted split-ring resonators is proposed and investigated. The simulated and measured results show that the proposed metamaterial can achieve efficient asymmetric transmission of linearly polarized wave and cross-polarization conversion for two distinct bands: X (6.95–10.05 GHz) and Ku (15.55–18.47 GHz). In the X-band, an incident y-polarized wave is almost converted to a x-polarized wave, while an incident x-polarized wave is completely blocked from passing through the structure. In the Ku-band, an incident x-polarized wave is almost converted to a y-polarized wave, while an incident y-polarized wave is blocked from passing through the structure. Moreover, the simulated and measured results confirm that the proposed metamaterial has a good robustness to misalignment, which provides convenience for fabricating in practical applications. Finally, the physical mechanism of this dual-band asymmetric transmission effect can be explained based on the different resonant modes of the proposed structure.