基于微波光子的复合式时频传输技术研究

Research on composite time-frequency transmissiontechnology based on microwave photonics

光载射频传输技术在地基无源探测、分布式阵列合成孔径、空间探测等诸多领域具有广泛的应用,用于实现不同子阵之间的信号互连与信号相参。针对传统光载射频传输技术中相位稳定度低、时延变化大、易受环境影响等问题,本文提出一种复合式微波光子时频传输技术,通过结合被动和主动时频传输技术,分别实现了本振点频信号的光纤分发和中频宽带信号的光纤回传,联合两者之间技术优势实现了系统的相位高稳定度和宽带信号传输的目的。本系统可实现本振信号、中频信号在中心端和远端的时频稳相传输。通过对比实验和综合测试,实现1.6 GHz本振和(1.6±0.5)GHz中频信号的稳相传输,传输距离为5 km,经过在-40~+70℃的环境试验验证,温度变化范围内上下行微波光子链路中相位波动小于±1.5°。

Optical radio-frequency transmission technology has a wide range of applications in ground-based passive detection,distributed array synthetic aperture,and space detection,and many other areas,used to achieve signal interconnection and signal coherence between different sub-arrays.In this paper,a composite microwave photonic time-frequency transmission technology is proposed in this paper to address the problems of low phase stability,large time delay variation,and susceptibility to environmental influences in traditional optical Radio over fiber technology.By combining passive and active time-frequency transmission technology,the fiber distribution of the local oscillator point frequency signal and the fiber return transmission of the intermediate frequency broadband signal are achieved respectively,and the technical advantages of the two are combined to achieve the purpose of the system′s high stability of the phase and broadband signal transmission.This system can realize the time-frequency stable phase transmission of the local oscillator signal and the intermediate frequency signal at the center end and the remote end.Through comparative experiments and comprehensive tests,the stable phase transmission of 1.6 GHz local oscillator and(1.6±0.5)GHz intermediate frequency signal is realized,and the transmission distance is 5 km.After environmental test verification at-40~70℃,the phase fluctuation in the upstream and downstream microwave photonics link within the temperature change range is less than±1.5°.