Microwave Photonic Vector Signal Processing Technology

In recent years,with the development of communication technology,people's demand for large-capacity and high-rate information transmission is increasing.In order to meet the needs of society,it is necessary to use vector signals of different modulation formats for information transmission,which can improve communication transmission rate and spectrum utilization.Therefore,vector signal processing is a key technology for many communication systems such as satellite communication and mobile communication.However,the use of electronic system to process vector signals faces electronic bottlenecks such as small bandwidth and poor frequency tuning.Microwave photonics,as an interdisciplinary combination of microwave technology and photonics technology,has many advantages such as large bandwidth,good frequency tuning and anti-electromagnetic interference.It can solve the electronic bottlenecks of traditional electronic systems.Compared with traditional electronic systems,vector signal processing technology based on microwave photonics has significant advantages.In this thesis,we study vector signal processing technology based on microwave photonics.The main work is as follows:1.A vector signal generation scheme based on cascaded dual-drive Mach-Zehnder modulator(DDMZM)is proposed and simulated.This scheme uses a single DDMZM to convert I and Q baseband waveforms from the electrical domain to optical domain.Simulation results show that this scheme is stable and has good quality for vector signal generation in the frequency range of 10-60 GHz.2.A vector signal generation scheme based on dual-drive dual-parallel Mach-Zehnder modulator(DD-DPMZM)is proposed and simulated.This scheme has a compact structure by only using one electro-optic modulator.Simulation results show that this scheme can generate frequency-doubling vector signal and simultaneously reduce the requirement of the local oscillator signal.For example,by using local oscillator signal with low frequency can realize frequency-doubling vector signal generation.At the same time,this scheme operates on the same polarization state,which avoids the influence of the system link on the polarization state stability.3.A double Mach-Zehnder modulator(MZM)cascaded vector signal demodulation scheme based on faraday rotating mirror is studied.This scheme uses the faraday rotating mirror to rotate the polarization state of the optical sideband to realize vector signal demodulation.The structure is clever and the scheme realizes frequency-doubled vector signal demodulation by using one-frequency local oscillator signal.4.A vector signal demodulation scheme based on cascaded Mach-Zehnder modulator(MZM)is studied.This scheme utilizes two cascaded MZMs to modulate RF vector signal and local oscillator signal respectively in two orthogonal polarization states,which is simple in structure and easy to operate.Simulation results show that the scheme has a good frequency tunability and system stability in the frequency range of 10-60 GHz.5.A vector signal demodulation scheme based on DP-QPSK modulator is proposed and simulated.This scheme only uses one highly integrated electro-optic modulator without using of any optical filters,which reduces the number of components and has a compact structure.Simulation verification shows that this scheme can demodulate vector signals with different modulation formats well.Compared with the previous schemes,this scheme has a better frequency tunability and system stability in the frequency range of 10-60 GHz.