Broadband Spin-Selective Transmission Based on Dual-Layer 3D Chiral Metamaterial

Achieving polarization control of circularly polarized waves is of pivotal importance in the satellite communication, yet it poses a great challenge in broad operation band. This paper designs a dual-layer stereo structure to achieve efficient polarization separation of circularly polarized waves, which is composed of planar helices and foam blocks based on chiral metamaterial. The unit can effectively reflect the incident left-hand circularly polarized (LCP) wave, while allow the right-hand circularly polarized (RCP) wave to pass through it. The mechanism of spin selection is analyzed by the current distributions under the excitations of LCP and RCP waves. Numerical results show that the structure can effectively reflect LCP wave and transmit RCP wave within 9.1-15.4 GHz. The reflection and transmission efficiency are both above 0.9 and the fractional bandwidth reaches 51.4%.