矢量网络分析仪的时频域阻抗测量技术

由于传输线阻抗不连续性导致的串扰问题会严重影响信号传输的质量，从而导致信号完整性问题。从矢量网络分析仪阻抗测试原理出发，通过对比网络仪开路校准及端口补偿后的Smith圆图测量结果、阻抗和相位格式测量结果，说明网络仪频域3种测量格式所表述的阻抗信息；利用矢量网络分析仪时域变换功能从时域上对传输线进行评估，可以获得传输线阻抗不连续点和各位置阻抗信息。最后通过对一段3.5 mm传输线的测试，说明如何利用矢量网络分析仪的频域和时域同时对传输线特性尤其是阻抗特性进行评估，为传输线测试提供了一种新的方法。

Frequency and time domain impedance test technique based on VNA

Crosstalk caused by discontinuities of transmission lines can seriously affect the quality of signal transmission, which leads to the problem of signal integrity. By introducing the principle of impedance test in vector network analyzer, and comparing the open response calibrated measurement result under Smith chart format, port extension compensated Smith chart format, impedance format and phase format, the paper describes the information stated by these three different formats under frequency domain; Using time transform function of the vector network analyzer to evaluate transmission line under time domain, that can get the transmission line impedance and the impedance discontinuity location information. The measurement result of a 3.5 mm transmission line explains how to use the vector network analyzer to evaluate the impedance characteristics of one transmission line under both frequency and time domain; this provides a new method for transmission line test.