频率差计基本原理的探讨  

Discussion about the principle of differential frequency meter

作　　者：郑世林[1] 余佑财[2] 

机构地区：[1]咸宁学院物理系,咸宁437000 [2]咸宁职业技术学院,咸宁437000

出　　处：《电子测量技术》2006年第6期7-8,20,共3页Electronic Measurement Technology

基　　金：湖北省教育厅2004科学研究重点项目(2004D005)资助

摘　　要：在很多频率控制或频率数字化处理的场合,经常要求取得2个交变信号瞬时频率差的精确控制信号。以往实验中是采用2个频率计分别测量频率值,然后计算频率差进行数据分析,这样做显然不能实现瞬时反应,更无法得到与频率差对应的控制信号。采用输出频率差的频率差计是最佳途径。文中提出采用乘法器和积分器等组成频率差计,乘法器输出含有频率差成分的混合信号,合理设计积分电路的时间常数,提高高频抑制比,就可以得到精确的瞬时频率差信号。该方法区分度高、电路简单,很容易与整个工作系统整合为一体,使得电路更紧凑、工作更可靠。Accurate measurement of differential frequency is very important on the occasion of frequency control. In the traditional way, two frequency meters were used to measure the frequency independently, and then calculate frequency difference. In this paper, multiplier and integrator are used to form differential frequency meter. The multiplier outputs mixed signal which contains the information of differential frequency. If the time constant of integration circuit is properly set to improve high frequency restrain ratio to get accurate differential frequency signal. The resolution is high, and the circuit is simple.

关 键 词：频率差计 传输特性 高频抑制比 

分 类 号：TN912.27[电子电信—通信与信息系统]