Efficient asymmetric transmission for wide incidence angles using bi-layered chiral metasurface
Muhammad Ismail Khan, Bin Hu, Aroosa Amanat, Naeem Ullah, M. Junaid Iqbal Khan, Ata Ur Rahman Khalid
Abstract
Abstract An ultrathin bi-layered chiral metasurface manifesting asymmetric transmission for linear polarization is designed and experimentally demonstrated. By breaking certain symmetries of the chiral structure, the proposed design is enabled to convert a y -polarized wave into an x -polarized upon transmission in the forward direction with transmission coefficient 0.95 while an x -polarized wave is completely reflected. On the other hand, in the backward direction, an x -polarized wave is transformed into y -polarized with transmission coefficient magnitude of 0.95 while a y -polarized wave is reflected. More importantly, the proposed structure maintains asymmetric transmission characteristics for oblique incidence up to 60º both for transverse electric and transverse magnetic polarizations. It is shown that unlike linear polarization, the proposed metasurface shows no propagation direction-dependent characteristics for circular polarization. The ultrathin thickness (0.026λ at 10 GHz), efficiency and high angular stability qualifies the proposed metasurface to be a promising candidate for integration with numerous microwave devices.