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Phase Stabilized Transmission Technology Of Microwave Signal In Optical Fiber Link Based On Passive Phase Compensation

Posted on:2020-03-14Degree:MasterType:Thesis
Country:ChinaCandidate:Y JiangFull Text:PDF
GTID:2428330590496438Subject:Information and Communication Engineering
Abstract/Summary:PDF Full Text Request
In order to meet the requirements in the fields of radar,space observation and navigation,phase-stabilized transmission of microwave signal has become a hot topic.Due to the features of low loss,strong immunity to electromagnetic interference and light weight,optical fiber is considered as an excellent medium to transmit microwave signal over a long distance.However,the time delay of fiber link changes with the environment influence,which leads to a phase fluctuation of the recovered microwave signal.In this thesis,a phase-stabilized microwave signal transmission technology via optical fiber link is studied using passive phase correction,which aims to address the problems of limited compensation range,slow correction speed and low efficiency of the current phase-stabilized transmission schemes.Firstly,point-to-point phase-stabilized microwave signal transmission is investigated.At the local end,the microwave signal is divided into two paths by using the power splitter,where they are used as the reference signal and the detection signal after frequency division respectively.The reference signal is mixed with the detection signal after a round-trip transmission via optical fiber,to obtain a down-converted signal.Then,the down-converted signal is transmitted to the remote site through the same fiber link to mix with the detection signal for one-trip transmission,to generate a stabilized microwave signal.The current-mode switching mixer and variable gain amplifier are used to overcome the problem of low isolation of the frequency mixer effectively.Without phase or delay tunable device,the phase fluctuation introduced by fiber link can be eliminated by frequency mixing,so it is possible to realize phase-stabilized microwave signal transmission with fast correction speed,large compensation range and long transmission distance.Experimental results show that in a 25-km fiber link the root mean square(RMS)timing jitter of a 2-GHz signal is 1.40 ps.Then,two schemes of point-to-multipoint phase-stabilized transmission,including multilink and single-link distribution structures,are studied.There is no interference between the remote users under the architecture of multi-link distribution for the use of different optical fibers.The detection signal backward is mixed with the down-converted signal forward at different nodes in the same fiber,to obtain a phase-stabilized up-converted signal under the single-link distribution architecture.Experimental results show that the RMS timing jitter of a 2-GHz signal transmitted in the multi-link distribution structure with a 10-km fiber link is 0.968 ps,and the RMS timing jitter of the single-link distribution structure with a 11-km fiber link is 1.606 ps.This thesis focuses on phase-stabilized microwave signal transmission via optical fiber link,which overcomes the impact of low isolation of the frequency mixer effectively,by using current-mode switching mixer and variable gain amplifier.In addition,the point-to-multipoint phase-stabilized transmission under the multi-link distribution and single-link distribution architectures are experimentally demonstrated.
Keywords/Search Tags:microwave photonics, phase-stabilized transmission, phase fluctuation, frequency mixing
PDF Full Text Request
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