Analysis Of Crystal Oscillator Phase Noise Under Vibration Condition And Research On Compensation Processing Technology

In communication?navigation satellite, precision guided munitions and radar, frequency reference sources is one of the most important part, and its stability directly determines the performance of the equipment. With the continuous development of modern technology, the higher requirements of the frequency reference is gradually improving. Therefore, it is an urgent need to develop the frequency reference source with low phase noise, high stability.Because of high Q value, crystal oscillator is the most extensive time frequency source. But the crystal oscillator has the force-frequency characteristics, the parameters of quartz crystal will change in vibration conditions, which lead to phase noise increasing, and reducing the various kinds of electronic equipment performance in vibration environment. And analyses the influence of vibration on Spaceborne Radar Frequency Synthesizer and the communication system.According to the phase noise of crystal oscillator which is one of the most important index, introducing the concept of phase noise and its characterization methods, analyzing the crystal oscillator phase noise model based on Leeson model and Robins model, introducing three kinds of commonly used phase noise measurement method and measurement principle. Analyzing the effect of vibration on the phase noise of the crystal oscillator in theory and validating it through vibration experiment. Due to small size and light quality characteristics of crystal oscillator,we build a small crystal vibration platform, which can meet the majority of vibration environmental requirements of the crystal oscillator vibration compensation. Analyzing the acceleration sensitive vector spindle of crystal oscillator, and designing a device which can calibrate acceleration sensitivity vector spindle of crystal oscillator.the principle of electronic compensation based on digital controller is put forward to,analyzing the delay of electronic compensation, and coming to the conclusion that the electronic compensation is suitable for low frequency vibration compensation through experiments. mechanical damping structure of wire rope and rubber pad is designed respectively, and a theoretical model based on wire rope damper is simulated and analyzed, the conclusion that the mechanical buffer is suitable for high frequency vibration compensation is get. Proposing a hybrid compensation method which combines electronic compensation that is effectively at low frequency and mechanical buffering that is effective at high-frequency. Experimental results show that the phase noise of crystal oscillator get a very significant improvement(20dB or more) at 10~2kHz random vibration.