石英晶体动态电容的测试方法研究

Investigation on Measurement of Motional Capacitance

相位偏置法作为IEC推荐的石英晶体的动态电容标准测试方法,由于其对π网络制作工艺的严格要求,以及相位差精确测量的困难等原因,使得这种方法的实现比较困难,国内未见这方面的研究成果报道;介绍了相位偏置法测试石英晶体动态电容的方法,首次提出了主动补偿杂散电抗及石英晶体静电容C0所引起的附加相移的方法,降低了对π网络制作工艺的要求,同时也不需要为补偿C0所采用的补偿电路,使得相位偏移法更易于实现并推广使用;实验结果表明,本系统对石英晶体动态电容的测试精度可以达到±5%。

Phase offset measurement method is a standard method for measurement of motional capacitance of quartz crystal recommen ded by the LEC. However, its strict requirements on fabrication technology for ？ network, and difficulty in high accuracy measurement of phase offset, make it difficult to be realized. Up to now, there is no domestic research report on this topic. Here, the measurement method of motional capaeitance of quartz crystal with phase offset is presented. Active compensation to additional-phase shift induced by stray react ante and quartz crystal static capacitance （Co） is proposed, which reduce the requirements on fabrication technology for network without the compensation circuit for Co, which facilitates its wide applications. The experimental result indicates that the measurement accuracy of motional capacitance in quartz crystal can be up to （7% with this measurement system.