国家授时中心高精度光纤微波频率传递研究进展

Progress of high-resolution fiber-based microwave frequency dissemination in NTSC

为了实现远距离用户间的高精度频率信号同步,以及满足高精度地基授时系统的建设需求,中国科学院国家授时中心开展了高精度光纤微波频率传递研究。利用微波相位补偿方案,在112 km实地光纤上实现了高精度微波频率传递,获得了4.2×10^(-15)@1 s和1.6×10^(-18)@1 d的传递稳定度。与光学相位补偿方案相比微波相位补偿方案的实验结构更加简单,更加廉价,更适合大规模的工程建设。结合地基授时系统的长距离光纤微波频率的传递需求,基于同样的微波相位补偿方案,搭建了3套单段100 km的光纤微波频率传递系统,在300 km的光纤卷轴上进行了级联传递实验,获得了1.1×10^(-14)@1 s和6.8×10^(-18)@10^(5)s的传递稳定度,该实验结果对高精度地基授时系统的建设有着支撑作用。

In order to achieve the synchronization of the high-precision frequency signal between the long-distance users and meet construction needs of the High-precision Ground-based Time Service System,the National Time Service Center (NTSC) has carried out the research on fiber-based microwave frequency transmission.Based on microwave phase compensation,the single-stage microwave frequency dissemination experiment via a 112 km urban fiber was carried out,and an instability of 4.2×10^(-15)at 1 s and 1.6×10^(-18)at 1 d was achieved.Furthermore,a cascaded fiber-based microwave frequency dissemination experiment was carried out via 300 km fiber spools with three 100 km single-stage dissemination systems,exhibiting an instability of1.1×10^(-14)at 1 s and 6.8×10^(-18)at 10^(5)s.Compared to the optical phase compensation scheme,the microwave phase compensation scheme is of sample structure and less pricy,and is thus more suitable for large-scale engineering construction.The results of this research are a good support for the construction of the High-precision Ground-based Time Service System.