提出一种相位自校准的光纤微波频率相位传递方案。该方案使用声表面波滤波器的冲激响应的窄带信号作为时间信号，使其与频率信号可同时使用同一波长进行传输。为实现稳定的可重复相位差，利用时间信号的往返传输时延来确定频率信号的整数个周期，并在多次重启的情况下验证了系统相位的稳定性。在60 km实验室平台上对所提方案进行验证，频率传递的稳定度优于4×10-14@1s，5×10-17@10000s。系统多次重启的情况下，所获得的平均相位差最大不一致的峰峰值为0.008 rad，对应于整个周期的0.15%，可保证较高的相位一致性。

As basic physical quantities, time and frequency are the research basis of many applied fields, such as verification of basic physics, clock-based geodetic survey, positioning and navigation. Optical fiber is an ideal medium for high stability time-frequency transmission due to its advantages of low loss, large bandwidth and strong anti-electromagnetic interference. At present, mainstream frequency transmission schemes can be roughly divided into optical frequency, optical frequency comb and radio frequency transmission. However, most of the existing time-frequency transmission systems can only guarantee a constant phase difference during the operation of the system, and ignore the phase difference change that may occur after relocking when the system is restarted or the system link length is changed. This situation cannot meet the needs of some coherent applications, such as distributed phased array radar, radio telescope arrays. These applications not only require stable phase difference during operation, but also require that the value of phase difference does not change after multiple restarts, which can provide reference signals of the same frequency and phase between different sites to achieve more effective coherent processing.In this paper, an absolute phase transfer scheme for optical fiber radio frequency based on adjustable optical delay line is proposed. The scheme makes full use of the round-trip transmission delay of the time signal to determine the integer period of the phase of frequency signal. Combined with the high precision phase measurement of microwave frequency, a microwave frequency signal with a fixed phase difference between the remote signal and the local signal can be obtained when the system is shut down and restarted for many times. In this scheme, 1PPS signal is not directly used as a time reference signal. First, RC differential circuit and avalanche triple laser are used to convert 1PPS signal into narrow pulse signal, and then surface acoustic wave filter is used to filter the narrow pulse signal to obtain the narrow band time reference signal. By means of frequency division multiplexing, time signal and microwave frequency signal are coupled in the same wavelength channel for transmission so as to avoid the delay difference introduced in different wavelength transmission. The system uses the way of wavelength division multiplexing to transmit. The return time frequency signal is obtained by a loop method and compared with the local reference signal to obtain the round-trip link delay and link cumulative phase. The cumulative phase of the link is used as an error signal to control the optical delay line to stabilize the link, and then the absolute phase transmission is realized by using the calculated link delay to calibrate the integer period of frequency signal. Compared with other time-frequency co-transmission modes, the system of this scheme is simpler. It does not need to adopt multiple modulation modes, nor does it directly modulate 1PPS signal. Narrow-band filter can be used to separate the time signal from the microwave frequency signal so that they do not affect each other.The experiment was carried out on a 60 km optical fiber link. After transmission, the system obtained a frequency stability of better than 4×10^-14@1 s, 5×10^-17@10 000 s. After the link is stabilized, the measured stability of time transfer (TDEV) is 10 ps@1 s and 0.3 ps@10 000 s. The results show that this scheme has good link compensation effect. When the system is restarted several times, the maximum inconsistency of the average phase difference is 0.008 rad, corresponding to 0.15% of the whole cycle, which can ensure the realization of good phase consistency.