Optical phase transfer via fiber optics is the most effective method for optical frequency standard comparison on the scale below thousands of kilometers.However,the monotonic phase discrimination range of conventiona...Optical phase transfer via fiber optics is the most effective method for optical frequency standard comparison on the scale below thousands of kilometers.However,the monotonic phase discrimination range of conventional optical phase-locked loops is limited,and link delays restrict the control bandwidth,which makes it a challenge to achieve a continuously reliable optical link.This paper presents an event-timing-based phase detection method that overcomes the monotonic phase discrimination range limitation of conventional phase-locked loops through dual-edge timestamp recording,achieving an optical phase measurement resolution on the order of 10 attoseconds.With such a technique,we established a 7-segment-cascaded optical link over 1402km of commercial fiber while sharing dense wavelength division multiplexing(DWDM)channels with live telecom traffic.The system maintained continuous operation for 11.7 days without phase cycle slips despite encountering 15 km aerial fiber noise up to 21000 rad^(2)·Hz^(−1)·km^(−1)at 1 Hz.Relative instabilities of the link are 3.7×10^(−15)at 1 s and 3.9×10^(−20)at 100000 s.展开更多
The analysis of stability and numerical simulation of Costas loop circuits for the high-frequency signals is a challenging task. The problem lies in the fact that it is necessary to observe very fast time scale of inp...The analysis of stability and numerical simulation of Costas loop circuits for the high-frequency signals is a challenging task. The problem lies in the fact that it is necessary to observe very fast time scale of input signals and slow time scale of signal s phases simultaneously. To overcome this difficulty, it is possible to follow the classical ideas of Gardner and Viterbi to construct a mathematical model of Costas loop, in which only slow time change of signal s phases and frequencies is considered. Such an construction, in turn,requires the computation of phase detector characteristic, depending on the waveforms of the considered signals. In this paper, the problems of nonlinear analysis of Costas loops and the approaches to the simulation of the classical Costas loop, the quadrature phase shift keying(QPSK) Costas loop, and the two-phase Costas loop are discussed. The analytical method for the computation of phase detector characteristics of Costas loops is described.展开更多
分布式发电因可避免远距离电能输送而被重视,作为配套产品的并网控制器将有较大的市场需求空间。该设计围绕并网技术指标展开,旨在实现可靠并网发电。首先,基于软硬件锁相环研究提出并网监控设计方案。其次,在软件锁相环的DSP程序算法中...分布式发电因可避免远距离电能输送而被重视,作为配套产品的并网控制器将有较大的市场需求空间。该设计围绕并网技术指标展开,旨在实现可靠并网发电。首先,基于软硬件锁相环研究提出并网监控设计方案。其次,在软件锁相环的DSP程序算法中,利用移动平均滤波器的锁相环(moving average filter based PLL,MAF-PLL)作为小型双馈风力发电并网控制数据采集与检测技术;在硬件锁相环设计中,通过电压提取与比较、锁存、驱动触发多环节电路设计实现并网信息检测;硬软件锁相环结合用于实际双馈发电系统的定子电压控制。最后,基于可靠通信设计实现系统联调,电网侧与发电侧电压参数被准确采集与监控,相位差控制在13°以内,电压差在1%以内,指标基本符合国家标准。展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2020YFC2200103)the Shandong Provincial Natural Science Foundation(Grant Nos.ZR2022LLZ006 and ZR2022LLZ011)+1 种基金the Innovation Program for Quantum Science and Technology(Grant Nos.2021ZD0300904 and 2021ZD0300903)the Key R&D Plan of Shandong Province(Grant No.2023CXPT105)。
文摘Optical phase transfer via fiber optics is the most effective method for optical frequency standard comparison on the scale below thousands of kilometers.However,the monotonic phase discrimination range of conventional optical phase-locked loops is limited,and link delays restrict the control bandwidth,which makes it a challenge to achieve a continuously reliable optical link.This paper presents an event-timing-based phase detection method that overcomes the monotonic phase discrimination range limitation of conventional phase-locked loops through dual-edge timestamp recording,achieving an optical phase measurement resolution on the order of 10 attoseconds.With such a technique,we established a 7-segment-cascaded optical link over 1402km of commercial fiber while sharing dense wavelength division multiplexing(DWDM)channels with live telecom traffic.The system maintained continuous operation for 11.7 days without phase cycle slips despite encountering 15 km aerial fiber noise up to 21000 rad^(2)·Hz^(−1)·km^(−1)at 1 Hz.Relative instabilities of the link are 3.7×10^(−15)at 1 s and 3.9×10^(−20)at 100000 s.
基金supported by Academy of Finland,Russian Ministryof Education and Science(Federal Target Program)Russian Foundation for Basic Research and Saint-Petersburg State University
文摘The analysis of stability and numerical simulation of Costas loop circuits for the high-frequency signals is a challenging task. The problem lies in the fact that it is necessary to observe very fast time scale of input signals and slow time scale of signal s phases simultaneously. To overcome this difficulty, it is possible to follow the classical ideas of Gardner and Viterbi to construct a mathematical model of Costas loop, in which only slow time change of signal s phases and frequencies is considered. Such an construction, in turn,requires the computation of phase detector characteristic, depending on the waveforms of the considered signals. In this paper, the problems of nonlinear analysis of Costas loops and the approaches to the simulation of the classical Costas loop, the quadrature phase shift keying(QPSK) Costas loop, and the two-phase Costas loop are discussed. The analytical method for the computation of phase detector characteristics of Costas loops is described.
文摘分布式发电因可避免远距离电能输送而被重视,作为配套产品的并网控制器将有较大的市场需求空间。该设计围绕并网技术指标展开,旨在实现可靠并网发电。首先,基于软硬件锁相环研究提出并网监控设计方案。其次,在软件锁相环的DSP程序算法中,利用移动平均滤波器的锁相环(moving average filter based PLL,MAF-PLL)作为小型双馈风力发电并网控制数据采集与检测技术;在硬件锁相环设计中,通过电压提取与比较、锁存、驱动触发多环节电路设计实现并网信息检测;硬软件锁相环结合用于实际双馈发电系统的定子电压控制。最后,基于可靠通信设计实现系统联调,电网侧与发电侧电压参数被准确采集与监控,相位差控制在13°以内,电压差在1%以内,指标基本符合国家标准。
