Research On Photonics-based Highg-quality Microwave Signal Generation And Remote Phase-stabilized Transmission Technology

The generation and distribution of microwave signal plays an important role in the field of moden radar,communication and electronic warfare.Due to the limited bandwidth of the electronic devices,it is difficult to produce the signal with high frequency and high quanlity from the conventional signal source.Optoelectronic oscillator(OEO),one of the novel microwave signal source,can produce the microwave signal with high frequency and ultra pure spectrum and the optical pulse with low time drift.The optical fiber as energy storage medium is used to construct the high quanlity-factor resonator.In this thesis,the basic principle of the OEO is introduced and the parameters as initial condition,signal frequency and amplitude of the OEO are deduced.The spectrum characteristics and noise source of the OEO are investigated.By optimizating the parameters of the devices and system structure,we can improve the phase noise performance of OEO.Then a novel OEO based on Brillouin-Induced phase shift is proposed and validated by theoretical analysis and experiement.The long-term stability of a wideband tunable OEO is investigated.An intermediate frequency phase-locked technique is proposed.As for the signal remote dissemination,the phase drift from the optical fiber is eliminated by a passive phase fluctuation cancellation scheme.Stable radio frequency dissemination in a multi-access link and reverse transmission from remote site are proposed and validated by experiement.The major innovations and contributions are as follows:1.The overall loop gain of OEO is optimized.The effects of nonlinear effects of the electro-optic modulator and the RF amplifier on the output power of the OEO are analyzed.The phase noise of the OEO is optimized for different nonlinear constraints.Based on the theoretical description of the power distribution of the dual-loop OEO,the relationship between the phase noise degradation factor and the distribution power and the loop length is obtained and the power allocation is optimized.The influence of the inherent phase difference of the injection lock on the phase noise is analyzed for the first time.The system is optimized by simulation and experiments.2.A novel OEO based on the fiber-induced Brillouin effect is proposed.The optical carrier phase shift technology based on Brillouin slow light effect realizes the phase modulation to intensity modulation conversion.Then the signal is injected into the phase modulator to form a positive feedback loop.Further combining the dispersion-induced power attenuation effect,a reconfigurable microwave photonic filter and the corresponding tunable OEO are designed.3.A scheme based on intermediate frequency phase-locked technology to solve the long-term stability of broadband-tuned OEO is proposed.By frequency conversion,an intermediate frequency link is constructed,and a phase-locked loop module is designed by directly split part of the intermediate frequency signal from the intermediate frequency link.The long-term stable output of broadband-tuned OEO is achieved.The stability has nothing to do with the oscillation frequency by experimental verification.4.For long-distance signal transmission technology,a new type of passive phase-stabilization transmission scheme is proposed to solve the link jitter introduced in the transmission process.At the same time,multi-user access can be achieved.In addition,for the wideband signal reception,a stable phase backhaul technology is designed to simplify the remote structure,and the multi-band signals can be received and processed by changing the local devices.