Microwave Photonic Jamming Technology Of False Targets And Its Photonic Integration

Radar systems are developing towards high frequency,large bandwidth,multi-band and distributed.Traditional electronic radar jamming technology is limited by electronic bottleneck,and is difficult to achieve effective interference to modern radar system.Featuring to the natural advantages of ultra-high working frequency,ultra-large frequency bandwidth,ultra-low loss and anti-electromagnetic interference,microwave photonics technology combined with radar interference technology become an effective way to solve various technical bottlenecks in electronic jamming technology.However,the current jamming technology based on microwave photonics is in the early stage of development,and most of them are still based on discrete component links,so the system consumes a lot of power,is bulky,and has low reliability.In view of the above problems,this paper mainly studies the microwave photonic radar jamming technology,and designs three microwave photonic jamming signal generation schemes.The specific research contents are as follows:1.The research background of microwave photonic jamming technology and photonic integration technology is expounded,and the common devices and principles of microwave photonic systems are listed and analyzed,and the commonly used radar interference technology is studied and discussed in detail.2.An interrupted sampling and direct repeater jamming signal generation scheme based on polarization division multiplexing Mach-Zehnder modulator(PDM-MZM)is designed.Through the photoelectric conversion of the balanced photodetector(BPD),the scheme uses PDM-MZM to modulate radar signals and interrupted sampling signals to obtain jamming signals which can generate multiple false targets.In the simulation,for a chirp signal with a time width of 10 μs and a frequency range from 3 GHz to 4 GHz,an interrupted sampled direct repeater jamming signals has been generated.When the duty cycle is set to 50%,several false targets can be obtained.The interference performance under different duty cycle and interrupted sampling repetition period is analyzed and verified.The feasibility of the scheme for photonic integration is verified in the photonic integration software Lumerical.3.A cosine phase-modulated jamming signal generator based on dual parallel Mach-Zehnder modulator(DP-MZM)and phase modulator(PM)is designed.In this scheme,DP-MZM and PM are employed to modulate the intercepted radar signal and cosine signal respectively.After photoelectric conversion by photoelectric detector(PD),the jamming signal of multiple false targets can achieve multiple frequency shift jamming effect.In the simulation,a jamming signal for a time width of 10 μs and a frequency range of 3 GHz to 4 GHz chirp signal is generated.After pulse compression,nine false targets with an interval of 0.1 μs can be obtained.The influence on the number and interval of false targets is discussed and verified as the carrier frequency of the RF signal and the modulation index changing.At the same time,the feasibility of photonic integration is verified in the photonic integration software Lumerical.4.A generation scheme of interrupted sampling frequency shift complex jamming signal based on PDM-MZM and Sagnac loop is designed.The scheme uses PDM-MZM to modulate the intercepted radar signal and the interrupted sampling signal,and uses Sagnac loop to modulate the RF signal.After photoelectric conversion by BPD,the signal that can realize the dense false targets jamming can be obtained.In the simulation,for a time width of 10 μs and a frequency range of 3 GHz to 4 GHz chirp signal,the dense false targets jamming with the coverage range of 0.4 μs is generated.The influence on the number,spacing and distribution of false targets is analyzed and verified by simulation for the different duty cycle,repetition period,modulation index and RF signal frequency.The feasibility of the photonic integrated scheme is verified in the photonic integration software Lumerical.