基于注入锁定光电振荡器的远距离微波频率高精度实时同步关键技术研究

Cooperative observations of multiple points in a large geographical area are widely applied in many fields, such as astronomical observation, radar network detection, etc. Therefore, it is imperative that the frequencies of different observation points are precisely synchronized in real-time. Now, the long-term stability of the frequency synchronization is already improved by optical fiber transmission with the feedback compensation technology. The short-term stability which can be deteriorated by the fast varying interference of the transmission path is still unsolved. However, the short-term stability is very import in most of the applications..In this project, we proposed a new frequency synchronization technique, which is based on the injection locked optoelectronic oscillator technology, to solve the short-term stability problem of the frequency synchronization. The main features of this technique can be described as following. First, it can inhibit the high-frequency disturbance caused by the transmission, by taking advantage of the super energy storage ability of the optoelectronic oscillator. Second, it can make an adaptive tracking of the frequency, with the help of the injected locking technique and the cavity stabilization of the optoelectronic oscillator. Third, it can avoid mode hopping of the oscillator by double-resonator. Furthermore, the proposed technique can also be used to achieve high-precision real-time frequency synchronization under the condition of lossy transmission path. It also has potential advantages on the synchronization of multiple points or very long distance transmission..A frequency synchronization system will be designed to validate this introduced synchronization technique. The performance indexes of the system are supposed to be as following: the working frequency is 10GHz; the transmission distance is 100 km; the long-term stability is better than 10-15@1s; as for the short-term stability, the phase noise level should be reduced to below 10-8rad2•Hz@1KHz.

大范围多点协同观测在天文观测、雷达网探测等领域有广泛应用，这要求各点间频率高精度实时同步。目前通过光纤传输采用反馈预补偿的方案基本解决了频率同步的长时稳定性问题。但对于传输线路的快变干扰导致的短时稳定性恶化目前还没有有效的解决方案，而短时稳定性指标在很多应用场合是非常重要的。.申请对频率同步短时稳定性问题，提出了基于注入锁定光电振荡的解决方案：利用光电振荡器强储能能力抑制传输产生的高频扰动；用注入锁定和光电振荡器腔长稳定实现频率自适应跟踪；提出双环谐振解决振荡器跳模问题等办法，提高频率同步的短时稳定性。进而结合现有方案，解决了有损信道条件下高精度、远距离的实时频率同步问题。此外本方案在支持多点和超长距离同步也有优势。.作为验证，完成10GHz传输100km的频率同步系统。长期稳定性优于10-15@1秒；短期稳定性，相位噪声下降10-8dB@1KHz。为高精度频率同步提供一种有效的解决方案。

大范围多点协同观测在天文观测、雷达网探测等领域有广泛应用，这要求各点间频率高精度实时同步。目前通过光纤传输采用反馈预补偿的方案基本解决了频率同步的长时稳定性问题。但对于传输线路的快变干扰导致的短时稳定性恶化目前还没有有效的解决方案，而短时稳定性指标在很多应用场合是非常重要的。.申请对频率同步短时稳定性问题，提出了基于注入锁定光电振荡的解决方案：利用光电振荡器强储能能力抑制传输产生的高频扰动；用注入锁定和光电振荡器腔长稳定实现频率自适应跟踪；提出双环谐振解决振荡器跳模问题等办法，提高频率同步的短时稳定性。进而结合现有方案，解决了有损信道条件下高精度、远距离的实时频率同步问题。此外本方案在支持多点和超长距离同步也有优势。.作为验证，完成10GHz传输100km的频率同步系统。长期稳定性优于10-15@1秒；短期稳定性，相位噪声下降10-8dB@1KHz。为高精度频率同步提供一种有效的解决方案。.针对研究目标提出的研究内容，研究完成了偏振双环保证光电振荡器的单频振荡技术长稳技术的研究，同时完成光电振荡器优化设计，确保光电振荡器能够实现对光注入信号稳定锁定，长期稳定性达到10-20，相位噪声低于 80dB@1KHz。针对频率同步短时稳定性问题，进行了针对发射端的共轭相位补偿实验、针对长时间传输光纤的色散补偿实验和基于注入锁定的长腔光电振荡器的实验。利用DCF混合补偿方案，实现长光纤的色散补偿，提高传输能力；利用长腔光电振荡器的储能能力抑制传输产生的高频扰动；用注入锁定和光电振荡器腔长稳定实现频率自适应跟踪。完成了 10GHz 微波频率信号的两点频率传输实验，传输距离 100 公里，比较在接收端直接输出的频率信号与从光电振荡器输出的频率信号的长期稳定性和相位噪声情况，验证采用并完成三个节点上频率分配系统实验，验证频率传输精度，并进行精度比较，符合研究目标要求。