基于信号传输延迟的频率测量方法

Method of frequency measurement based on signal transmission delay

提出了一种通过信号传输延迟来提高频率测量精确度的方法。该方法利用多根延时相同的传输线对被测信号进行延时,形成延时总和为一个基准信号的周期性多路被测信号的延时信号,通过选取与比较基准信号跳变沿前后相邻的两个延时时间的平均值作为基准信号上升沿与闸门开始及终止之间的时间差,以计算被测信号的频率。误差分析和测量不确定度评定表明:该方法测量精确度由延时时间决定。实验数据证明:该方法在保证测量速度的同时有效减小了±1计数误差。

A new method is proposed for high-precision frequency measurement according to the signal transmission delay principle. The method adopts multi-strip transmission lines to generate multi-channel de- layed signal whose period is almost the same with that of the reference signal. The average delay time of two adjacent signals whose edges are mostly near to the reference signalls edge is selected as the in- terval between the reference signalls rising edge and the gaters falling edge to calculate the frequency of the measured signal. Error analysis and measurement uncertainty evaluation show that the accuracy of measurement of the me-thod depends on the delayed time. The experiment data verify that the method can effectively reduce the test error by one reference-pulse cycle while guaranteeing the testing speed.