Anti-vibration Design Of Spaceborne Crystal Oscillator

Crystal oscillator is widely used in satellite electronic products and plays an important role.It is widely used in various subsystems,such as navigation,data transmission,measurement and control subsystems.Crystal oscillator frequency provides clock and local oscillator signals for all kinds of single computers through frequency doubling and frequency synthesizing.Therefore,the performance of single machine and even the performance of whole satellite will be directly determined by the quality of crystal oscillator index.Because crystal oscillation is very sensitive to vibration,frequency drift and phase noise will occur when it is subjected to vibration,which will affect the quality of output signal of crystal oscillation,and violent vibration will occur when satellite is launched.Therefore,the anti-vibration performance of crystal oscillation is particularly important for those single computers that need to be booted up in the process of launching,which will directly affect the success of satellite launching.In order to ensure the safety and reliability of satellite launching and on-orbit operation,it is necessary to improve the anti-vibration performance of satellite-borne crystal oscillator in order to meet the practical requirements.The purpose of this thesis is to improve the anti-vibration performance of spaceborne crystal oscillator.By analyzing the working principle of spaceborne crystal oscillator and the influence of vibration environment on the performance of crystal oscillator,the anti-vibration analysis and design of spaceborne crystal oscillator structure are completed,and the design results are verified by experiments.The main contents of this thesis are as follows:1.The working principle and types of crystal oscillator and the dynamic environment analysis of crystal oscillator are introduced.2.The vibration mechanism of quartz resonator is analyzed.The concept of phase noise of crystal oscillator is introduced.The influence of vibration on the performance of crystal oscillator is analyzed.The calculating formula is deduced.3.The analysis and design of anti-vibration of crystal oscillator are summarized.The shortcomings of traditional anti-vibration design of crystal oscillator are summarized.The simulation model of crystal oscillator module is established by using MSC.Patran 2012 software according to the actual needs of engineering.The anti-vibration design is optimized from four aspects: anti-vibration design of crystal oscillator shell,anti-vibration design of printed circuit board,vibration isolation design of crystal oscillator and vibration reduction design of crystal oscillator module.The results were analyzed and calculated by MSC.Nastran 2012.4.A random vibration test system and a phase noise measurement system are introduced and built.Random vibration tests are carried out according to typical space-borne crystal vibration test conditions to verify the vibration transmission characteristics of the anti-vibration design and the improvement of crystal phase noise.The experimental data show that the anti-vibration design can effectively improve the phase noise level of crystal vibration in the vibration environment.The research results of this thesis effectively solve the problem of adaptability of space-borne crystal oscillator mechanics environment.The vibration reduction effect and phase noise level of crystal oscillator meet the requirements of Engineering application,and lay a foundation for the future anti-vibration design of crystal oscillator.