高精度调频式电容位移传感器

摘要

This paper designed non-contact FM displacement capacitance sensor,which was based on the difference frequency FM technology. The circuit was consisted of two sin signal generators, down-conversion circuit and discriminator. Experimental results show that resolution of 5 run can be achieved by this sensor, and it has good linearity.%设计了一种单极板调频式电容位移传感器,可实现非接触微位移测量.其原理为通过双路差频方法得到位移-频率的调制信号,再由乘法器鉴频得到位移变化量.电路包括测头及LC振荡电路、本振电路、混频下变频电路和鉴频电路.实验表明该传感器分辨力达到5 nm,并具有较好的线性度.