一种用于高速差分线的宽带共模噪声滤波器

A Wideband Common-Mode Noise Filter for High-Speed Differential Lines

提出了一种用于高速差分线的新型宽带共模噪声滤波器,通过在差分信号线的参考地平面上刻蚀共面波导形式的1/4波长谐振器进行实现.建立了该结构的等效电路模型,分析结果与全波电磁仿真以及实验测量结果一致.结果表明,滤波器在3.96~8.26GHz频率范围内实现了20dB的共模噪声抑制,同时保证良好的差分信号传输特性.与已有设计相比,在尺寸、成本和性能上具有综合优势.

A novel wideband and low cost filter is designed for common mode noise suppression in high- speed differential signaling. It is realized by etching coplanar waveguide quarter-wavelength resonators on the ground plane beneath the center of differential lines. An equivalent circuit model is developed to evalu- ate the effectiveness of the proposed structure, which is in good agreement with the full-wave simulation and measurement. It is found that the common mode noise can be suppressed over 20 dB from 3.93 to 8.26 GHz by the proposed filter while good transmission characteristic is maintained for the differential signals. Compared with other designs, the combination of size, cost, and performance of the proposed filter is very competitive.