精密频率与相位调整方法

摘要

The precision frequency and phase adjustment method is a key technology of time keeping system.The direct digital synthesizer(DDS)is used to introduce the precision frequency and phase adjustment amount.The output of DDS is locked at oven controlled crystal oscillator(OCXO)through phase locked loop(PLL). A frequency divider and a two-stage frequency difference multiplication are utilized in PLL to improve the frequency and phase adjustment resolution. The output of the OCXO after PLL locking acts as the signal after frequency and phase precise adjustment. The test system based on phase comparison was designed for frequency and phase adjustment resolution. The experimental results show that the frequency adjustment resolu-tion of the system can reach up to 4×10-17,and the phase adjustment resolution can reach up to 6 fs.%精密频率与相位调整技术是守时系统的关键技术.利用直接数字频率合成(DDS)引入精密频率与相位调整量,通过锁相环将DDS输出锁定于本地恒温晶振OCXO,在锁相环中通过分频和两级频差倍增提升频率和相位调整分辨率,环路锁定后的OCXO输出即频率和相位精密微调后的信号.设计了基于相位比对的频率和相位调整分辨率测试系统,实验结果表明,精密频率与相位调整系统的频率调整分辨率达到了4×10-17,相位调整分辨率达到了6 fs.