Research On Fiber-optical ARFM And DRFM Mixed Technology

Radio frequency memory(RFM)technology can preserve radar signal and produce replicas of radar waveforms or quasi-replication after certain specified modulations when needed.Therefore,there is a good correlation between the jamming signal generated by the RFM and the radar signal.RFM technology often used to generate jamming signals or target analog signals.RFM is mainly classified into analog radio frequency memory(ARFM)and digital radio frequency memory(DRFM).Fiber-Optical ARFM is a kind of ARFM,which used fiber delay line unit as the storage frequency unit.Due to its large instantaneous bandwidth,short response time and high storage accuracy,Fiber-Optical ARFM has become the main method of ARFM.DRFM uses digital memory to store signal.It has the advantages of long storage time,convenient time-frequency modulation and flexible parameter control,which is widely applied to practical engineering.Fiber-Optical ARFM has low jamming performance,and DRFM has long response time and poor real-time capability.Combing Fiber-Optical ARFM and DRFM,this thesis proposes Fiber-Optical ARFM and DRFM Mixed technology,and its application in radar jamming is studied.The performance of FiberOptical ARFM and DRFM Mixed technology has been greatly improved compared to the previous single Fiber-Optical ARFM or single DRFM.Firstly,the principle of radar jamming patterns such as RF noise jamming and noise amplitude modulation jamming is studied,and the characteristics of these jamming patterns are analyzed and simulation experiments are conducted,which provides a theoretical basis for the subsequent application of Fiber-Optical ARFM and DRFM Mixed.Secondly,the realization structure,frequency storage unit and performance indicators of Fiber-Optical ARFM technology are studied.The realization structure,quantification method and performance indicators of DRFM technology are analyzed.Based on this,the realization method of broadband DRFM is studied.At the same time,the quasi-sample pulsed frequency storage is analyzed.Finally,the advantages and disadvantages of Fiber-Optical ARFM technology and DRFM technology are discussed.The signal delay time of Fiber-Optical ARFM technology is inconvenient to adjust,besides this,Fiber-Optical ARFM technology can not form a large number of dense pseudo-targets,and DRFM has limited instantaneous bandwidth and long system response time.In order to solve above problems,Fiber-Optical ARFM technology and DRFM technology are combined,and the Fiber-Optical ARFM and DRFM Mixed technology is proposed.The structure of Fiber-Optical ARFM and DRFM Mixed system is analyzed,and jamming patterns generated by Fiber-Optical ARFM and DRFM Mixed is studied,and performance indicators of Fiber-Optical ARFM and DRFM Mixed technology are discussed.Besides this,jamming experiments on LFM signal radar and phase encoding signal radar are conducted.The experimental results show that the jamming signals generated by the Fiber-Optical ARFM and DRFM Mixed technology has a good jamming effects on the LFM signal radar and the phase encoding signal radar.