In this letter, a compact dual-band dual-mode substrate integrated waveguide (SIW) balanced band-pass filter (BPF) with intrinsic common-mode (CM) suppression is designed by using a single perturbed SIW circular cavity. The vias and slot perturbations are introduced to tune the resonant modes TE ₀₁₀ , TE ₁₁₀ (a pair of degenerate modes), and TE ₂₁₀ of a circular cavity. Thus, they can be used to form two differential-mode (DM) passbands with independently adjustable center frequencies and bandwidths. The SIW can be seen as a natural balun with intrinsic CM suppression. Furthermore, the planar differential excitation structure is designed to excite the perturbed SIW cavity. The CM noise cannot excite SIW cavity due to the characteristics of hybrid electromagnetic boundary. Finally, a compact dual-band dual-mode SIW balanced BPF at 8 and 10 GHz is designed and fabricated, and the measured results show good agreement with the simulated ones.

中文翻译：

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具有固有共模抑制功能的紧凑型双频双模式SIW平衡BPF

在这封信中，通过使用单个扰动的SIW圆形腔，设计了具有固有共模（CM）抑制的紧凑型双频双模衬底集成波导（SIW）平衡带通滤波器（BPF）。引入通孔和缝隙扰动以调谐谐振模式TE ₀₁₀ ，TE ₁₁₀（一对简并模式）和TE ₂₁₀圆形空腔。因此，它们可用于形成两个具有独立可调中心频率和带宽的差模（DM）通带。SIW可以看作是具有固有CM抑制功能的自然巴伦。此外，平面差分激励结构被设计为激励被扰动的SIW腔。由于混合电磁边界的特性，CM噪声不能激发SIW腔。最后，设计并制作了紧凑的双频双模SIW平衡BPF，频率分别为8 GHz和10 GHz，测量结果与仿真结果吻合良好。