PCB阻抗测试研究

Study on PCB impendence measurement

信号高频、高速化发展对信号完整性要求越来越严格,阻抗匹配性成为信号完整性至关重要问题。PCB阻抗测试准确性受测试方法、设备差异等因素影响,因此如何准确、有效测试PCB阻抗越来越受到人们的关注。文章探讨了阻抗测试设备类型、测试方式、阻抗线长、迹线取值区间对PCB阻抗测试结果的影响,并进一步分析了采用不同设备测试非常规阻抗结果的差异性,给出了不同设备非常规阻抗的测试方法,对PCB阻抗测试具有指导意义。

With the improvement of signal transmission frequency and speed, the requirement is more and more strict with signal integrity(SI). Meanwhile, impedance matching is becoming issue of crucial importance. The accuracy of PCB impedance measurement is related to measuring method and equipment differentiation, so how to measure PCB impedance accurately and effectively has been widely concerned. The effect of equipment varieties, test styles, impedance line lengths, range of trace on the results of PCB impedance measurement was studied. Simultaneously, the variety of results measured by different equipments for unconventional impedance was also investigated, and the methods of measuring unconventional impedance were also provided which have great significance for directing PCB impedance measurement.