用双混频时差法测量频率的相位差和频率稳定度

0μs~99999 . 9μs ,该时间信号是由 5MHz 混频器产生 1 秒信号,所以要Р乘上 5MHz 的倒数 2 ×10 - 7 , 代表值为: ( 2 ×10 - 7 )Р00000 . 0p s~200ns 。Р×00000 . 0μs~ ( 2 ×10 - 7 ) ×999999 . 9μs , 即Рb. 时差测量分辩率为 0 . 1p s (0 . 1μs 位 5 个数字) 。Рc . 时差测量准确度为 10p s (100μs 位 5 个数字) 。Р2 . 自校测量频率稳定度Р两个频率输入端 f a , f b 同时接到一个频率源上,所看到的就是本机的噪声。见下表:Р自校测量频率稳定度РP HASE D EVIATIO N OF FREQUENCY ANDРFREQUENCY STABIL ITY MEAS URED BY THE METHOD OF D UAL MIXER TIME D IFFERENCEРShen J iliang?Cai Yong Ma NanxueР( Shanghai Astronomical Observatory , Chinese Academy of Sciences , Shanghai 200030)РAbstractРThe performance and theory of a kind of dual - mixer measurement instrument were detail described.РKey words?time — parison — time keeping —frequency standardРσy (τ)Рσy (100 )Рσy (101 )Рσy (102 )Рσy (103 )Р实测结果Р2 ×10 - 13Р2 ×10 - 14Р5 ×10 - 15Р2 ×10 - 15