In this paper, a kind of bi-layer extrinsic chiral metamaterial is proposed to realize asymmetric transmission (AT) of circularly polarized waves in the microwave region. We have studied numerically and experimentally the transmission properties of the proposed structure. The results show that under oblique incident wave the asymmetric transmission effect occurs with a 1.5 GHz operation band. The maximum value of AT parameter reaches up to 0.68 at the resonant frequency, which is larger than those in the extrinsic chiral metamaterials previously reported. This AT phenomenon is illustrated by the surface current distribution in detail. The transmission properties of the incident waves can be dynamically regulated by tuning the incident angles θ and ϕ. This metamaterial is potential in the polarization control applications.

中文翻译：

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双层外在手性超材料中圆偏振波的不对称传输

在本文中，提出了一种双层非本征手征超材料来实现圆偏振波在微波区域的非对称传输（AT）。我们已经通过数值和实验研究了所提出结构的传输特性。结果表明，在斜入射波下，非对称传输效应发生在 1.5 GHz 工作频段。AT 参数的最大值在共振频率下达到 0.68，大于先前报道的外在手性超材料中的最大值。这种 AT 现象由表面电流分布详细说明。可以通过调整入射角 θ 和 ϕ 来动态调节入射波的传输特性。这种超材料在偏振控制应用中具有潜力。