中文摘要：

以千兆以太网交换机PCB设计出现的问题为背景，研究高速数字电路设计的信号完整性问题，从板层、电源和传输线三方面分析原因，并提出解决方法，测试表明取得了有效的结果。

英文摘要：

This paper focuses on the signal integrity problems in designing high-speed digital circuit, which is encountered in PCB design of Ethernet Switch. After three aspects：PCB layout, power source and transmission line ,＇have been analyzed, some solutions are proposed and effectiveness has been proved to be feasible by testing.