印制电路板弯曲绕线对信号传输时延影响的研究

Study on signal propagation delay in serpentine PCB traces

高速印制电路板(PCB)布线通过弯曲绕线的方式,实现PCB布线的物理等长,此方式对信号传播会造成时延影响。通过简单的串扰理论分析,根据不同走线的弯曲状况,使用网络分析仪测试了弯曲走线的时延;再使用电子设计自动化(EDA)仿真软件,对设计的弯曲绕线进行时延仿真验证;最后将仿真与测试的时延结果进行对比,发现仿真与测试的时延结果一致性较好,验证了使用软件进行信号完整性仿真结果的正确性。此结果对PCB实际工程设计有较好的指导意义,最后给出对PCB设计中处理此类弯曲绕线时的工程经验建议。

When high speed signal propagates on serpentine PCB trace,signal’s propagation delay will be affected according to different style of serpentine traces.Crosstalk simple theory will be introduced.A PCB test board contained various style of serpentine traces was designed and manufactured.Signal propagated time on these serpentine traces were tested,signal integrity simulations based on these serpentine traces were made as well.The author finds out that the test result of signal propagation delay time of the test board and the signal integrity simulation result agree with each other well.Some engineering experience suggestions of PCB design serpentine trace were given in the end.