Signal-interference single- and multiband bandpass-type transversal filtering sections (TFSs) with input- and two-port low-reflection (LR) behavior are reported. These LR TFSs consist of the following three parts: 1) a reflective-type TFS shaped by two in-parallel unequal length transmission line segments; 2) a lossy open-ended stub shunted at the input or both at the input and output nodes of the building reflective-type TFS for the input- and two-port-LR TFS cases, respectively; and 3) input/output power-matching transmission line sections. In this manner, the stopband RF-signal energy that is not transmitted by the reflective-type TFS is dissipated by the resistor(s) of the lossy open-ended stub(s) instead of being reflected back to the source. This allows LR capabilities to be obtained in the overall modified TFSs. The operational principles of the proposed input- and two-port-LR TFSs, along with theoretical design examples and their comparison, are presented. Moreover, multi-TFS-stage LR bandpass filters (BPFs) are shown. They are based on the in-series cascade of several LR TFSs to enlarge the bandwidth and power rejection levels of the stopbands while keeping their LR nature. For experimental validation purposes, microstrip prototypes of a three-TFS-stage BPF with broadened input-LR stopbands and a quintuple-band input-LR TFS are developed and characterized.

中文翻译：

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具有分流损耗短截线的低反射信号干扰单通带和多通带滤波器

报告了具有输入和两端口低反射 (LR) 行为的信号干扰单频带和多频带带通型横向滤波部分 (TFS)。这些LR TFS由以下三部分组成：1）由两个平行的不等长传输线段形成的反射型TFS；2) 分别在输入和双端口 LR TFS 情况下在建筑物反射型 TFS 的输入或输入和输出节点处分流的有损开端短截线；3)输入/输出功率匹配传输线段。以这种方式，未被反射型 TFS 传输的阻带 RF 信号能量由有损开端短截线的电阻器耗散，而不是被反射回源。这允许在整体修改的 TFS 中获得 LR 能力。介绍了所提出的输入和两端口 LR TFS 的工作原理，以及理论设计示例及其比较。此外，还显示了多 TFS 级 LR 带通滤波器 (BPF)。它们基于多个 LR TFS 的串联级联，以扩大阻带的带宽和功率抑制水平，同时保持其 LR 性质。出于实验验证的目的，开发并表征了具有加宽输入 LR 阻带和五倍带输入 LR TFS 的三 TFS 级 BPF 的微带原型。它们基于多个 LR TFS 的串联级联，以扩大阻带的带宽和功率抑制水平，同时保持其 LR 性质。出于实验验证的目的，开发并表征了具有加宽输入 LR 阻带和五倍带输入 LR TFS 的三 TFS 级 BPF 的微带原型。它们基于多个 LR TFS 的串联级联，以扩大阻带的带宽和功率抑制水平，同时保持其 LR 性质。出于实验验证的目的，开发并表征了具有加宽输入 LR 阻带和五倍带输入 LR TFS 的三 TFS 级 BPF 的微带原型。