Asymmetric transmission (AT) through metasurfaces yields a direction-sensitive behavior for electromagnetic (EM) wave propagation. To date, majority of the reported works operate at normal incidences alone and are, therefore, highly prone to variations under oblique incidences. In contrast, the chiral metasurface presented in this letter is robust up to 60$^{\circ }$ incident angle while yielding a transmission magnitude above 80% for an operational-range of 8.1–9.3 GHz in a thin bilayered configuration. Furthermore, since a miniaturized unit-cell is the key to angular robustness of the metasurface, a lumped-model development methodology to determine its resonant frequency is presented. Lastly, it is shown that the reported metasurface can geometrically be scaled to the lower ends of microwave spectrum, thus increasing its utility for mainstream applications. The results have been analytically and experimentally validated and yield state-of-the-art features in comparison to previous works in microwave regime.

中文翻译：

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用于非对称传输的双层、宽带、角度稳健的手性超表面

通过超表面的非对称传输 (AT) 产生了电磁 (EM) 波传播的方向敏感行为。迄今为止，大多数报道的作品仅以正常入射角运行，因此在倾斜入射角下极易发生变化。相比之下，这封信中提出的手性超表面在高达 60$^{\circ}$ 入射角时是稳健的，同时在薄双层配置中在 8.1-9.3 GHz 的操作范围内产生超过 80% 的传输幅度。此外，由于微型单元是超表面角稳健性的关键，因此提出了一种确定其共振频率的集总模型开发方法。最后，表明报告的超表面可以几何缩放到微波光谱的低端，从而增加其对主流应用程序的效用。与之前在微波领域的工作相比，结果已经过分析和实验验证，并产生了最先进的特征。