This letter presents new configurations of stubbed waveguide cavities for the realization of pseudo-elliptic and self-equalized filters. The basic structure consists of a main TE₁₀₂/TE₂₀₁ dual-mode cavity that is loaded with a pair of waveguide stubs. The two stubs are located at the top and bottom walls of the cavity while always being parallel and in-line to each other. Such a two-stub arrangement can be seen as a TM₁₁₀ mode cavity, which is embedded into the main dual-mode cavity. By properly setting the polarization of the stubs with respect to the main cavity as well as finely adjusting the difference between the lengths of the stubs, triple-resonance structures with selected topologies and controllable coupling mechanisms can be implemented. The resulting third-order filtering functions comprise three poles and two zeros, the latter being either group delay equalization zeros or finite frequency transmission zeros depending on the polarization of the stubs. The experimental results of a fifth-order filter with two finite frequency transmission zeros using one stubbed waveguide cavity between two standard cavities validate the new configuration.

中文翻译：

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使用短截波导双模腔的新三谐振配置

这封信介绍了用于实现伪椭圆和自均衡滤波器的短波导腔的新配置。基本结构由一个主 TE ₁₀₂ /TE ₂₀₁双模腔组成，该腔装有一对波导短截线。两个短截线位于空腔的顶壁和底壁，同时始终彼此平行且成一直线。这种双截线布置可以看作是 TM ₁₁₀模腔，嵌入到主双模腔中。通过适当设置短截线相对于主腔的极化以及微调短截线长度之间的差异，可以实现具有选定拓扑和可控耦合机制的三重谐振结构。得到的三阶滤波函数包括三个极点和两个零点，后者是群延迟均衡零点或有限频率传输零点，具体取决于短截线的极化。具有两个有限频率传输零点的五阶滤波器在两个标准腔之间使用一个短波导腔的实验结果验证了新配置。