A compact triple-mode bandpass filter (BPF) based on a modified rectangular substrate integrated waveguide (SIW) cavity is presented. The perturbation of the dominant mode (TE₁₀₁) and the third resonance mode (TE₁₀₂) are realized by two metalized vias in order to keep the first three resonant modes evenly distributed in the passband. Using this strategy, we can control both bandwidth and finite-transmission zero (FTZ). The bandwidth of BPF can be controlled by simply changing the diameter of the metalized vias. Coaxial excitation is used to achieve a parallel coupling with small external quality factor, resulting in a wideband response. The proposed triple-mode SIW BPF also has an FTZ, which is decided by the angle between two feeds. In order to verify the proposed strategy, two samples with a center frequency of 5.5 GHz have been designed and manufactured.

中文翻译：

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基于使用同轴馈电的单微扰衬底集成波导腔的紧凑型三模带通滤波器

提出了一种基于改进的矩形衬底集成波导 (SIW) 腔的紧凑型三模带通滤波器 (BPF)。主模式 (TE ₁₀₁ ) 和第三谐振模式 (TE ₁₀₂ )的扰动) 由两个金属化过孔实现，以保持前三个谐振模式在通带中均匀分布。使用这种策略，我们可以控制带宽和有限传输零 (FTZ)。BPF 的带宽可以通过简单地改变金属化过孔的直径来控制。同轴激励用于实现具有较小外部品质因数的并联耦合，从而产生宽带响应。建议的三模 SIW BPF 也有一个 FTZ，这是由两个馈电之间的角度决定的。为了验证所提出的策略，设计并制造了两个中心频率为 5.5 GHz 的样品。