Research On Photonic Generation Of Phase-coded Microwave Signal And Microwave Angle-of-arrival Measurement

Photonic generation of phase-coded signals and microwave Angle-of-arrival measurement are essential technologies in modern radar,communications,and electronic reconnaissance.In recent years,with the rapid development of terahertz technology,the radio frequency band has gradually increased.Traditional electronic technology in the phase-coded signal generation and microwave Angle-of-arrival measurement faces limited bandwidth,high transmission loss,severe electromagnetic interference,large volume and other electronic bottlenecks.Cannot meet the development needs of future radar,electronic reconnaissance and other fields.Photonic generation of phase-coded microwave waveforms technology has the advantages of high carrier frequency,large time-bandwidth product,and low transmission loss,etc;the photonic microwave Angle-of-arrival measurement technology has the advantages of wide carrier frequency range,a large tunable range,and high direction finding accuracy.And both of them can effectively resist electromagnetic interference,less affected by environmental factors,so they have been widely studied by many scholars.However,most of the existing photonic generation of phase-coded microwave waveforms techniques have low tunable range,complex modulator modes and cannot be directly applied to radar systems because of their inability to generate radar pulses;photonic microwave Angle-of-arrival measurement techniques have poor ability to screen target signals,and the system is redundant.In view of the above problems,theoretical,simulation and experimental researches on the photonic generation of phase-coded microwave waveforms and microwave Angle-of-arrival measurement technologies are carried out in this paper.The detailed contents are as follow: 1.A phase-coded signal generation scheme based on dual-polarization modulator(Dpol-MZM),optical band-pass filter(OBPF)and phase modulator(PM)is proposed and simulated.This scheme does not use any electric phase shifter and electric power divider,which increases the carrier frequency tunable range of the system.The modulation method of the dual polarization modulator is simple and easy to implement.And the scheme can generate arbitrary phase-coded signals.2.A phase-coded signal generation scheme based on dual polarization modulator(Dpol-MZM),polarization modulator(PolM)and balance detector(BPD)is proposed and experimentally studied.This scheme does not use the filter,further improving the tunable range of the carrier frequency.It can not only generate a continuous phase-coded signal but also generate phase-coded pulses,and do not need to control the amplitude of the coded signal.In the experiment,6 and 11 GHz continuous phase-coded microwave waveforms and phase-coded pulses at 11 GHz are generated.The waveform generation quality and pulse compression performance of the phase-coded signals at each frequency are analyzed.The results are in accordance with the theoretical values.3.A microwave photonic Angle-of-arrival measurement scheme based on dual parallel Mach-Zehnder modulator(DP-MZM)is proposed and simulated.The overall idea of the scheme is to use microwave photonic technology to perform interferometric phase measurement and then use an interferometer to measure the Angle-of-arrival.Compared with other existing solutions,the system only uses an integrated external modulator,which increases the stability of the system.The use of mixing technology allows the system to accurately identify the target signal,so as to carry out accurate direction finding.