微波信号的稳相传输在雷达、空间观测以及卫星导航等领域有广泛的应用。针对目前点对点稳相传输方案传输效率不高以及主动补偿速度较慢等问题,研究并提出了一种基于被动补偿的适用于大范围、多站点微波信号光纤稳相传输的方案。微波信号在本地端经功分器分为两路,分别作为待传信号和分频后的探测信号;待传信号在本地端与经光纤往返传输的探测信号混频获得下变频信号;该下变频信号传输到远端与前向探测信号混频后生成相位稳定的微波信号,通过结构的合理设计实现点到多点稳相传输。经过实验验证后可知:2 GHz信号在10 km光纤链路下多链路分布结构的均方根(RMS)延时抖动为0.968 ps,在11 km光纤链路下单链路分布结构的均方根延时抖动达到1.606 ps。

Phase-stabilized microwave signal transmission has been widely used for radar, space observations, and satellite navigation. To address the problems of low transmission efficiency and slow speed of active compensation in a point-to-point phase-stabilized transmission scheme, herein, we propose a scheme for point-to-multipoint microwave signal transmission via optical fiber links using passive phase correction, which is required for achieving a large compensation range and multiple access points. At the local end, we use a power splitter to divide the microwave signal into two paths, which are used as the signal to be transmitted and detection signals after frequency division. The signal to be transmitted is mixed with the detection signal following a roundtrip transmission via the optical fiber to obtain a down-converted signal. The down-converted signal is then transmitted to the remote end through the same fiber link to be mixed with the forward detection signal for one-trip transmission. This generates a stabilized microwave signal, and the stable point-to-multipoint phase transmission is realized from a rational design of the structure. Experimental results show that the root mean square (RMS) timing jitter of a 2-GHz signal in this multi-link distributed structure is 0.968 ps across a 10-km fiber link, whereas the RMS timing jitter of a single-link distributed structure is 1.606 ps over an 11-km fiber link.