不同拐角差分传输线结构的信号完整性分析

随着PCB 设计中信号传输速度的增加，差分信号传输方式被更多的应用到实际布线中。但由于拐角处的差分线长度不一致，使得差分信号之间产生了相位差，从而造成共模噪声的出现影响了信号的完整性。本文对四种不同拐角的差分传输线结构进行了S 参数仿真，通过分析他们的共模噪声，得出了较小的拐角模型能抑制共模噪声的产生。并提出了有效减小共模噪声的方法。

The Signal Analysis of Different Bend Angle ofDifferential Transmission Line

With the increasing speed of transmission of digital circuit in the PCB design, increasingly differential signaltransmission lines have been used for layout. The different length of two transmission lines on the bend will cause a phase skewbetween the differential signals, and it result in common-mode noise emerged, which influenced signal integrity. S-parametersare analyzed by using four 3D models of different bend angles in this paper. Through the analysis of their common-mode noise,the result performs the lower angle model can inhibit the emergence of common-mode noise. Then the method to reduce thecommon-mode noise is proposed.