Novel cross-coupled dual-band bandpass filters (BPFs) with compact size are proposed based on dual-mode isosceles right-angled triangular (IRAT) resonators. The dominant mode in the IRAT resonator is the TM100Z mode. By introducing posts in the resonators, an LC resonant unit is formed, which resonates at a lower frequency than the TM100Z mode. In the design of novel dual-band filters, the LC mode constitutes the first passband while the TM100Z mode produces the second passband. As cross-coupling is applied, two and eight transmission zeros (TZs) are produced in the responses of third-order and fourth-order dual-band BPFs, respectively. Two third-order cross-coupled dual-band BPFs with altered passbands and one fourth-order cross-coupled dual-band BPF are fabricated and measured. The measured results agree very well with the simulated results, demonstrating attractive advantages of the proposed BPFs such as compact size and decent performance.

中文翻译：

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基于双模等腰直角三角形谐振器的新型紧凑尺寸交叉耦合双频带带通滤波器


基于双模等腰直角三角形（IRAT）谐振器，提出了尺寸紧凑的新型交叉耦合双带带通滤波器（BPF）。 IRAT 谐振器中的主要模式是 TM100Z 模式。通过在谐振器中引入柱子，形成 LC 谐振单元，其谐振频率低于 TM100Z 模式。在新型双带滤波器的设计中，LC 模式构成第一个通带，而 TM100Z 模式产生第二个通带。当应用交叉耦合时，三阶和四阶双频带 BPF 的响应中分别产生两个和八个传输零点 (TZ)。制作并测量了两个具有改变通带的三阶交叉耦合双频带通滤波器和一个四阶交叉耦合双带带通滤波器。测量结果与模拟结果非常吻合，证明了所提出的 BPF 的诱人优势，例如紧凑的尺寸和良好的性能。