In this article, high selectivity filtering antennas are designed based on a mixed-mode cavity resonator, which is formed by adding a short-circuited metal cylinder at the center of a rectangular cavity. The resonant and coupling characteristics of the proposed resonator are analyzed in detail. The operating modes of the mixed-mode cavity are TE ₁₀₂ mode, TE ₀₁₂ mode, and quasi-TEM mode, which can be utilized to design filtering antennas with different transmission zero distributions. To demonstrate the concept, three slot antennas with 3rd-order filtering performance are designed and simulated, where two transmission zeros are introduced to improve the selectivity. Furthermore, a 5th-order filtering antenna array based on the mixed-mode resonator is designed and fabricated. The measured results are consistent with the simulated results, showing that a gain of greater than 13 dBi is achieved.

中文翻译：

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使用混合模腔谐振器的高选择性波导滤波天线

本文设计了基于混合模腔谐振器的高选择性滤波天线，该谐振腔由在矩形腔体中心添加短路金属圆柱体构成。对所提出的谐振器的谐振和耦合特性进行了详细分析。混模腔的工作模式为TE ₁₀₂模式、TE ₀₁₂模式和准TEM模式，可用于设计具有不同传输零分布的滤波天线。为了演示这一概念，我们设计并模拟了三个具有三阶滤波性能的缝隙天线，其中引入了两个传输零点以提高选择性。此外，设计并制作了基于混模谐振器的五阶滤波天线阵列。实测结果与仿真结果一致，表明实现了大于 13 dBi 的增益。