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 TM ₁₀₀ ^Z mode. By introducing posts in the resonators, an LC resonant unit is formed, which resonates at a lower frequency than the TM ₁₀₀ ^Z mode. In the design of novel dual-band filters, the LC mode constitutes the first passband while the TM ₁₀₀ ^Z 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谐振器的紧凑型新型交叉耦合双带带通滤波器

基于双模等腰直角三角形 (IRAT) 谐振器，提出了具有紧凑尺寸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 TM ₁₀₀ ^Z模式。通过在谐振器中引入柱子，液晶显示器形成谐振单元，其谐振频率低于 TM ₁₀₀ ^Z模式。在设计新颖的双带滤波器时，液晶显示器模式构成第一个通带，而 TM ₁₀₀ ^Z模式产生第二个通带。由于应用了交叉耦合，三阶和四阶双频 BPF 的响应中分别产生了两个和八个传输零点 (TZ)。制造并测量了两个具有改变通带的三阶交叉耦合双频带 BPF 和一个四阶交叉耦合双频带 BPF。测量结果与模拟结果非常吻合，证明了所提出的 BPF 具有吸引力的优势，例如紧凑的尺寸和良好的性能。