A novel design of bandpass frequency selective surface (FSS) with high selectivity is proposed based on the antenna-filter-antenna (AFA) concept. Traditional AFA-based FSSs improve filtering performance by adding the order of resonator or the coupling paths. On account of the reciprocity theorem, transmission zeros are here introduced by the antenna's radiation null. The proposed FSS consists of two patch antennas connected with one pin and a C-type slot on the ground. The aforementioned structure generates two controllable radiation nulls related to the lengths of slots without any extra circuits. Therefore, two transmission zeros at both edges of the passband can be controlled by adjusting the dimension of slots. A prototype is fabricated and measured. Numerical simulation and measured results are in good agreement, which demonstrates that the proposed AFA-based FSS exhibits a quasi-elliptic bandpass response and a low profile.

中文翻译：

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利用贴片天线辐射零点的具有准椭圆带通响应的频率选择表面


基于天线-滤波器-天线（AFA）概念，提出了一种具有高选择性的带通频率选择表面（FSS）的新颖设计。传统的基于 AFA 的 FSS 通过添加谐振器阶数或耦合路径来提高滤波性能。由于互易定理，传输零点在此由天线的辐射零点引入。所提出的 FSS 由两个贴片天线组成，两个贴片天线通过一个引脚和地面上的 C 型槽连接。上述结构无需任何额外电路即可产生与缝隙长度相关的两个可控辐射零点。因此，通带两端的两个传输零点可以通过调整缝隙的尺寸来控制。制造并测量原型。数值模拟和测量结果非常一致，这表明所提出的基于 AFA 的 FSS 具有准椭圆带通响应和低轮廓。