SI9000软件的教程，非常详尽，希望对信号仿真的朋友有用,SI9000 software tutorial, very detailed, I hope the friends of the useful signal simulation

介绍如何使用SI9000进行阻抗计算。这种可以方便在画PCB的时候对走线加以指导。(Describes how to perform impedance calculations using the SI9000. This makes it easy to guide the line while painting the PCB.)