Research On Technology Of Microwave Photonic Vector Signal Processing

Due to the vigorous development of communication technology,communication frequency bands are becoming increasingly scarce,so it is an inevitable choice to improve spectrum utilization.In this regard,researchers have put forward the theory of vector signal generation.Traditional electronic devices have inherent defects.Therefore,the vector signal generated in the electrical domain has a small bandwidth,poor frequency coordination,and cannot be transmitted in a complex electromagnetic environment,which severely limits the increase in communication speed.Therefore,microwave photonics,which combines the advantages of photonics and microwave technology,has become a new direction to solve problems.It breaks the negative impact of the defects of traditional electrical devices on the system performance.It has the advantages of extremely large signal bandwidth,extremely high carrier frequency,low transmission loss,and small space occupied.It perfectly solves the problems encountered in electronic systems.Based on microwave photonics,this article mainly studies related technologies for processing vector signals in the optical domain.The work is as follows1.A vector signal generation scheme based on dual polarization binary phase shift keying(DP-BPSK)modulator is studied,the device and principle are introduced,the mathematical formula is deduced in detail,and the simulation verification and result analysis are finally carried out to realize the generation of high-quality vector signals with flexible and variable modulation formats.The error vector magnitude of the generated signal(such as QPSK signal,16 QAM signal)is less than about 5%,and it has been verified that the scheme has good frequency coordination and stability.When the carrier frequency is changed from 10 GHz to 60 GHz,The error vector amplitude of the generated vector signal remains basically unchanged,between 3.7% and 3.9%.The advantage of this scheme is that there is no filter in the structure,and the frequency tunable range is large.2.A vector signal generation scheme based on a dual-parallel quadrature phase shift keying(DP-QPSK)modulator is studied.The devices and principles of the scheme are introduced.Then,the feasibility of the method is tested by optical simulation software,and the method is realized.The generation of high-quality vector signals with flexible and variable modulation formats,the generated signal error vector amplitude is about 5%,and it is verified that a good-quality vector signal can also be generated under the condition of flexible changes in the received optical power.Finally,it is verified that the The system has good frequency tuning and stability.When the generated carrier frequency changes from10 GHz to 60 GHz,the error vector amplitude of the generated vector signal remains basically unchanged,and the floating interval is 1% and below.The advantage of this scheme is that it can generate a frequency-doubled vector signal without adjusting the polarization controller(PC)and polarizer(Pol)to achieve carrier cancellation.3.A vector signal demodulation scheme based on DP-QPSK modulator is studied,and its devices and principles are introduced.Then the feasibility of the method is tested by optical simulation software,and the High-quality demodulation of RF vector signal with flexible modulation format is realized.The amplitude of the demodulated signal error vector is about 3%.And we verified the frequency tunability of the scheme and the variability of RF signal power.When the received signal power varies from 0dBm to 22 dBm,the error vector amplitude of the demodulated signal is about 2% and stable.The advantage of this scheme is that the structure is compact and simple,the frequency requirement for the electric local oscillator is greatly reduced,and the frequency tunable range is large.