A new design methodology is presented for multi-band evanescent-mode band-pass filters (BPFs) realisation by integrating substrate-integrated waveguide structure with multiple short-circuited irises. The electro magnetic (EM)-behaviour of the distributed-element structure is modelled with the lumped-element equivalent circuit in a wide frequency range. Arbitrary transmission poles (TPs) and transmission zeros (TZs) corresponding to the different irises are characterised. Moreover, a rigorous prescribed filtering function is developed to design dual-band evanescent-mode BPFs in terms of independently tunable TPs and TZs. The proposed structure is reported to not only demonstrate miniaturised high quality-factor dual-band BPFs but also obviate the design challenges of multi-band BPFs below the cut-off frequency. Furthermore, two triple- and quadruple-band evanescent-mode BPFs are experimentally examined for the proposed concept verification.

中文翻译：

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双至四频带渐逝模式基片集成波导带通滤波器

通过集成具有多个短路虹膜的基片集成波导结构，提出了一种用于实现多频带-逝模式带通滤波器（BPF）的新设计方法。用集总元件等效电路在很宽的频率范围内对分布式元件结构的电磁（EM）行为进行建模。表征与不同光圈相对应的任意透射极点（TP）和透射零点（TZ）。此外，针对独立可调的TP和TZ，开发了严格的规定滤波功能以设计双频带e逝模式BPF。据报道，所提出的结构不仅展示了小型化的高质量因子双频带BPF，而且还消除了截止频率以下的多频带BPF的设计挑战。此外，