数字式双混频时差测量仪原理分析与仿真

摘要

In order to break through the limitations of traditional time frequency measuring technique and improve the preci-sion of the frequency stability,a digital dual mixer time difference measuring system is devised. The system is based on the tra-ditional dual mixer time difference measuring principle and the digital signal processing technique to realize the comparing mea-surement of the frequency scale. The simulation result shows that when measuring with the signal of 10MHz ,the Allan variance of the phase noise will be better than 3E-13/s,which can be used to real-time measure and monitor the frequency scale with high precision.%为了突破传统时频测量技术的局限性，提高频率稳定度的精确程度，研究设计了一套数字式双混频时差测量系统，采用经典双混频时差测量原理，运用数字信号处理技术实现频标的比对测量。仿真结果证明，采用10 MHz信号进行测量时，得到相位噪声Allan方差优于3E-13/s，可对高精度频标进行实时测量和监控。