In this paper, a bandpass filter (BPF) has been designed using bent and coupled-line structure. The design process of the filter to achieve a BPF with good characteristics is completely explained. Therefore the LC equivalent circuit of The BPF is presented as the analytical description. The proposed filter can pass frequencies between 2.2 and 3.6 GHz with an insertion loss <0.4 dB, which is suitable for wireless applications. The fractional bandwidths (FBW) of the filter is about 48%. Some characteristics such as small size, low insertion loss, high return loss wide upper stopband bandwidth, and good suppression level in stopband are among the advantages of this study to be mentioned. Finally, the presented filter was fabricated, and the measured results have a proper agreement with the simulation results.

中文翻译：

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用于无线应用的使用耦合线的小型带通滤波器

在本文中，使用弯曲和耦合线结构设计了带通滤波器（BPF）。完整解释了实现具有良好特性的 BPF 的滤波器设计过程。因此，BPF 的 LC 等效电路作为解析描述呈现。建议的滤波器可以通过 2.2 至 3.6 GHz 之间的频率，插入损耗 <0.4 dB，适用于无线应用。滤波器的分数带宽 (FBW) 约为 48%。一些特性，如小尺寸、低插入损耗、高回波损耗、宽上阻带带宽和良好的阻带抑制水平，是本研究要提及的优势之一。最后，制作了所提出的滤波器，并且测量结果与模拟结果具有适当的一致性。