Research On Microwave Photonic Channelized Receiver And Its Key Technologies

In traditional radar,communication,and electronic warfare systems,electronic technologies are usually adopted to process the microwave signals.In order to improve the system performance,future radar,communication,and electronic warfare systems are developing towards the directions of high frequency and large bandwidth.The instantaneous bandwidth of the signal will reach the GHz level,making it difficult to be directly processed by the electronic technologies.The channelized receiver can divide the large-bandwidth signal into multiple narrowband signals to reduce the processing pressure of the back-end,which can indirectly realize the processing of the large-bandwidth signal.However,the early channelized receiver is consisted of analog devices,which leads to poor channel balance,large size,weight,and power consumption.The digitally channelized receiver can solve the problem faced by the analog receiver.Nevertheless,limited by the performance of the existing analog-to-digital converter,the digitally channelized receiver is still difficult to meet the processing requirement of high-frequency and large-bandwidth signals,which severely limits the further development of radar,communication,and electronic warfare systems.As an emerging interdisciplinary subject,microwave photonics has the advantages of large bandwidth,low loss,immune to electromagnetic interference,small size,and light weight.Therefore,the channelized receiver can be developed by microwave photonics to mitigate the problems faced by the electronically channelized receiver.On one hand,the microwave photonic channelized receiver can divide the large-bandwidth signal into multiple narrowband signals.On the other hand,the multiple narrowband signals can be downconverted to the same intermediate frequency,which can achieve the channelization with same intermediate frequency.As the microwave photonic channelized receiver can solve the problems faced by the electrically channelized receiver,it has received extensive attention from scholars at home and abroad in recent years.To meet the signal processing requirement of the high-frequency and large-bandwidth in the future electronic systems,the microwave photonic channelized receiver and its key technologies are studied in this dissertation.Detailed research contents are as follows:In Chapter 2,the brief introduction of microwave photonic channelized receiver and its main technical indicators are given.Besides,the main problems of existing microwave photonic channelized receivers are pointed out.In order to solve the above problems,a microwave photonic channelized receiver based on optical comb polarization multiplexing and integrated coherent receiver(ICR)is proposed.It can achieve the channelization of the large-bandwidth signal without the need of multiple-comb-lines and large-interval optical comb.Moreover,in consideration of the problem that the high-frequency local oscillator signal is difficult to be generated in the electrical domain,an improved microwave photonic channelized receiver with the frequency doubling ability of the local oscillator signal is proposed.It only requires half frequency of the local oscillator signal to realize the microwave photonic channelization with the same working bandwidth.In Chapter 3,the microwave photonic image rejection technique is studied to solve the problem of severe image disturbance in the microwave photonic channelized receiver.By summarizing and analyzing the existing image rejection schemes,an image rejection scheme based on polarization division multiplexing mach-zehnder modulator(PDM-MZM)is proposed.With the advantages of large bandwidth and high gain,the proposed scheme can achieve the frequency conversion with high image rejection ratio.In Chapter 4,the microwave photonic linearization technique is studied to solve the problem of small spurious-free dynamic range(SFDR)of the microwave photonic channelized receiver.By summarizing and analyzing the existing microwave photonic linearization schemes,a microwave photonic linearization scheme based on dual-wavelength light source and phase modulator(PM)is proposed.With the advantages of large bandwidth,convenient operation,and high stability,the proposed scheme can improve the SFDR of the microwave photonic systems.In Chapter 5,the microwave photonic frequency converter with the elimination of periodic power fading and the high spectral efficiency radio over fiber(Ro F)link are studied to solve the problems of severe power periodic fading and low spectral efficiency in antenna remoting of the microwave photonic channelized receiver.A microwave photonic frequency converter based on dual-parallel mach-zehnder modulator(DPMZM)is proposed to simultaneously realize the frequency conversion and the elimination of the periodic power fading.The proposed scheme has the advantages of high gain,high isolation degree of the local oscillator signal,and simple structure.Besides,a high spectral efficiency Ro F link based on PDM-MZM is proposed to simultaneously realize the high spectral efficiency and the elimination of the periodic power fading,which has the advantages of convenient operation,simple structure,and low cost.In summary,to meet the high-frequency and large-bandwidth signal processing requirements of the future radar,communication,and electronic warfare systems,the microwave photonic channelized receiver and its key technologies are studied in this dissertation.A series of research results have been achieved: the proposed microwave photonic channelized receiver based on optical comb polarization multiplexing and ICR can alleviate the requirement of the multiple-comb-lines and large-interval optical comb;the proposed microwave photonic channelized receiver with frequency doubling ability can reduce the frequency requirement of the local oscillator signal;the proposed microwave photonic image rejection scheme based on PDM-MZM can be used to solve the problem of severe image interference in microwave photonic channelized receiver;the proposed linearization scheme based on dual-wavelength light source and PM can be applied to the microwave photonic channelized receiver to improve the SFDR;the proposed microwave photonic frequency converter based on DPMZM and the high spectral efficiency Ro F link based on PDM-MZM can respectively mitigate the problems of severe periodic power fading and low spectral efficiency in the antenna remoting of microwave photonic channelized receiver.