A chiral metasurface is proposed to realize a tri-band polarization angle insensitive cross-polarization converter. The unit cell of the chiral metamaterial is composed by four twisted anisotropic structure pairs in four-fold rotation symmetry. The simulation results show that this device can work at 9.824 GHz, 11.39 GHz, and 13.37 GHz with low loss and a high polarization conversion ratio （PCR） of more than 99%. The proposed design can transmit the co-polarization wave at 14.215 GHz, like a frequency selective surface. The study of the current and electric fields distributions indicates that the cross-polarization transmission is due to electric dipole coupling.
本文研究垂直入射条件下水平极化和垂直极化时金属开口谐振环(split ring resonator,SRR)的电磁响应行为.通过分析这两种情况下的透射系数、介电常数和磁导率,发现垂直极化时,SRR可以产生电谐振实现负介电常数,其频段远高于磁谐振频段;水平极化时,SRR只能产生磁谐振实现负磁导率,其频段与水平入射时的SRR的磁谐振频段相对应.通过仿真对此进行了证明,并对产生电谐振和磁谐振的原因进行了分析.
