获得高精度频率差的关键技术

The key technique to obtain high-precision data of the output frequency difference

在利用LC振荡电路的参数变化而引起振荡频率的变化的特性进行的多种应用测量实验中,测量结果的精度都依赖于频率差Δf=f-f0.但当电路校准后进入测量状态时,电路参数会发生改变,使初始频率f0不复存在.如何在进入测量状态后保持初始频率f0以及精确提取频率差Δf,是提高测量精度的关键.为此提出一种采用锁相环自锁定技术和频率差计的方法,可以取得较好的效果.

In many frequency measurement the accuracy of the data obtained is mainly depending on the frequency difference △ f= f- f0. Howerer, when the measurement is made, the original frequency f0 is disappeared. The trick using self-locking technique of PLL is reported and both f and △f can be measured accurately.