A novel miniaturized bandpass filter (BPF) with high stopband rejection based on a hybrid structure is proposed with shielded quarter-mode substrate integrated waveguide (QMSIW) and microstrip technologies. The shielded QMSIW cavity provides a high-quality ( $Q$ ) factor with substantial size reduction. This filter exhibits flexible response with four poles and two controllable transmission zeros (TZs) by incorporating two quarter-wavelength microstrip resonators into two back-to-back QMSIW resonators. The working principles for higher order mode suppression and filter coupling topology are carefully illustrated by eigen-mode simulation, coupling matrix, and field distribution analysis, respectively. Compared with the reported works, the proposed four-order BPF demonstrates advantageous features in terms of a compact size of $0.62\,\,\lambda _{0}\times 0.62 \,\,\lambda _{0}$ , a low insertion loss of 1.2 dB, a wide passband (22.7%), and a high stopband rejection (better than 36 dB).

中文翻译：

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基于四分之一模式基片集成波导和微带线谐振器的紧凑型，宽阻带屏蔽混合滤波器

提出了一种基于混合结构的，具有高阻带抑制比的新型小型带通滤波器（BPF），该技术采用屏蔽四分之一模式衬底集成波导（QMSIW）和微带技术。屏蔽的QMSIW腔提供了高质量的 $ Q $ ）尺寸大幅减少的因素。通过将两个四分之一波长微带谐振器合并到两个背对背QMSIW谐振器中，该滤波器具有四个极点和两个可控传输零点（TZ）的灵活响应。本征模式仿真，耦合矩阵和场分布分析分别详细说明了高阶模式抑制和滤波器耦合拓扑的工作原理。与报道的作品相比，拟议的四阶BPF展示了紧凑尺寸的优势特征。 $ 0.62 \，\，\ lambda _ {0} \ times 0.62 \，\，\ lambda _ {0} $ ，1.2 dB的低插入损耗，宽通带（22.7％）和高阻带抑制（优于36 dB）。