In this letter, a multilayer balanced substrate-integrated waveguide (SIW) bandpass filter (BPF) using the TE102 and TE201 modes is designed with an aperture etched on the common ground between two stacked SIWs. Under common-mode (CM) operation, the aperture is a perfect magnetic conductor (PMC). When the height is less than $\lambda _{g}$ /4, the space between the perfect electric conductor (PEC) and the PMC cannot transmit the electromagnetic wave, so the structure can effectively cutoff the CM noise in a wide frequency range. Under differential-mode (DM) operation, the aperture is the PEC and has less effect on the DM frequency responses by properly selecting the location and size. Two transmission zeros near the passband edges can be generated to improve the selectivity. Finally, a compact dual-mode balanced SIW BPF with high selectivity and CM suppression has been designed and fabricated, and the measured results show good agreement with the simulated ones.

中文翻译：

---

利用 PEC-PMC 特性进行共模抑制的多层双模平衡 SIW 滤波器

在这封信中，设计了一个使用 TE102 和 TE201 模式的多层平衡基板集成波导 (SIW) 带通滤波器 (BPF)，并在两个堆叠 SIW 之间的公共接地上蚀刻了一个孔径。在共模 (CM) 操作下，孔径是理想的磁导体 (PMC)。当高度小于$\lambda _{g}$ /4时，理想电导体（PEC）和PMC之间的空间不能传输电磁波，因此该结构可以在很宽的频率范围内有效地截断CM噪声. 在差模 (DM) 操作下，孔径是 PEC，通过正确选择位置和尺寸，对 DM 频率响应的影响较小。可以在通带边缘附近生成两个传输零点以提高选择性。最后，