数字式双混频时差测量系统的试验研究  

Experimental research on digital DMTD measurement system

作　　者：赵科佳[1] 张爱敏[1] 徐清华[1] 杨智君[1] 高小珣[1] 厉炜 

机构地区：[1]中国计量科学研究院,北京100013 [2]上海恩艾仪器有限公司,上海201203

出　　处：《仪器仪表学报》2014年第12期2858-2865,共8页Chinese Journal of Scientific Instrument

摘　　要：基于双混频时差测量原理,结合软件无线电的设计理念,设计数字式双混频时差测量系统模型,应用数学公式建模并推导相位差运算过程,在MATLAB环境下对频标信号和测量系统进行仿真实验,针对模数转换指标、数字鉴相方法和互相关算法提出关键技术解决方案。设计本底测量和比对测量实验方案,搭建数字式双混频时差实验设备,实验测量并计算分析实验数据。本底测量实验结果表明,实验设备秒稳本底指标优于5.0×10-13/1 s,达到国内领先水平。比对测量实验结果表明,实验设备测量结果与5120 A相近,其测量能力与测量性能优于频标比对设备PO7D-2和ST2002A。Based on the measurement principle of Dual Mixer Time Difference （DMTD） and the design concept of software-defined radio, the theoretical model of digital DMTD measurement system was designed; the phase difference was deduced according to the digital DMTD mathematical model; the frequency standard signals and measurement system were simulated in MATLAB environment. Some key technological solutions were proposed, including the specification of ADC, the method of digital phase discrimination, and the algorithm of cross correlation. The experiment schemes of noise floor and frequency standard comparison were designed. The experiment instrument of digital DMTD was established. The measurement experiments were conducted, and the experiment data were calculated and analyzed. The experiment result of noise floor indicates that the noise floor of experiment instrument for 1s frequency stability is better than 5.0×10^-13/1s, which is the leading domestic level. The experiment result of frequency standard comparison indicates that the measurement result of the experiment instrument is close to that of 5120A, the measurement capability and performance are better than those of PO7D-2 and ST2002A.

关 键 词：双混频时差 频标比对 阿伦标准偏差 数字鉴相 互相关 

分 类 号：TH7[机械工程—仪器科学与技术]