ABSTRACT This paper proposes a novel resonance structure to design a quad-band bandpass filter using open-end stub-loaded resonator, which consists of four resonant paths capable of independent control. Moreover, the resonators used to the coupled lines in order to create multiple transmission zeros. A quad-band filter that operates at frequencies of 2.1 GHz, 2.7 GHz, 3.5 GHz, and 4.7 GHz is designed with outstanding features including high selectivity without short-circuit stub-loaded resonator and low-cost single-layer printed circuit board process in selecting the individual passband. Good agreement between the simulation and experimental is achieved.

中文翻译：

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使用开端短截线加载谐振器的高选择性四带带通滤波器的设计

摘要本文提出了一种新颖的谐振结构来设计一个使用开放端短截线加载谐振器的四频带带通滤波器，它由四个能够独立控制的谐振路径组成。此外，谐振器用于耦合线以创建多个传输零点。在 2.1 GHz、2.7 GHz、3.5 GHz 和 4.7 GHz 频率下运行的四频滤波器设计具有出色的特性，包括高选择性、无短路短截线加载谐振器和低成本的单层印刷电路板工艺选择单个通带。实现了模拟和实验之间的良好一致性。