Generation Of Microwave Or Millimeter-wave Based On Polarization Scrambler And Polarization Maintaining Fiber

Mobile-broadband and broadband-mobile has become the goal of the development of telecommunication. RoF(Radio over Fiber) makes the sub-carrier of millimeter possible, realizing high capacity transmission and ultra wideband access. As the millimeter-wave generator plays a great role in RoF, it is very important to design effective microwave and millimeter wave generation device.In the paper, the generation of the millimeter-wave by optical method was studied and simulated. The main work of the thesis can be listed as follows:1. The schemes of optical heterodyning modulation were analyzed mainly. The models of the cases were built in principle. Comparing the advantages and shortness of the cases, the advice for development was proposed.2. The dispersion problem of the fiber and the principle Polarization Scrambler were discussed as well. Broadening of the Gauss Chirp pulse is analyzed mainly and the influence of the chirp parameter, the dispersion parameter and the length of the fiber was analyzed by simulation too.3. A new method was proposed to realize the generation of microwave and millimeter-wave by using polarization scrambler and polarization maintaining fiber (PMF). The basic idea was based on the coupling and the optical heterodyning interference between the two polarizations of the Gaussian optical pulse in PMF. The expression of the microwave and millimeter-wave was derived by couple-mode theory at last.4. The feasibility of the proposed system was analyzed by Matlab emulator. The emulated result indicated that the frequency of the microwave and millimeter-wave could be controlled by the dispersion parameter, the difference of the group delay, the length of the fiber, the input pulse-duration and the chirp parameter. At last, the property that 0～120 GHz frequency microwave and millimeter-wave could be produced by adjusting system-parameter or the parameter of the input pulse.5. The advantage of the proposed system was summarized. Polarization Scrambler made that the laser needn't keep stable polarization and each polarization in the PMF can be stable, keeping high coherent efficiency. Above all, the merit of the project was of great simplicity, stability and high export efficiency.