Related Characteristics Research Of Crystal Oscillators And Application Of The Border Effect

In this paper I am beginning from the working principle of crystal oscillator and make a detailed analysis on its physical characteristics, main parameter, common types, main influence factors and main circuit of vibration and mainly study the aging drifting and phase noise of crystal oscillator. For aging drifting, I analyze its generating causes and influence factors and seize its aging drifting rule to build an aging prediction math models,then compare existed aging data with predicting data to verify that this model built is proper, at last compensate its aging data. For the phase noise of crystal oscillator, I analyze its generating mechanism and by selecting components with low phase noise develop a crystal oscillator with lower phase noise.The border effect is a new theory, we can improve accuracy of measurement device by taking advantages of it. For crystal oscillator, from high resolution ratio,its resonance and oscillating do not happen at the same frequency but rather in a continuous range where resonance and oscillating continuously fluctuate, so a region where oscillating may happen is generated on both sides of strict resonance frequency and we call the area fuzzy area of crystal oscillator. Because of higher stability at its border of oscillating fuzzy area, we can improve it Q value by using the border effect of crystal oscillator.At last I make a detailed production and analysis on the border effect and deep study the border effect of crystal oscillator and its application. I design a double-crystal oscillation circuit where an AT cut crystal resonator with higher Q value is utilized to replace LC resonator filters for selecting frequency and filtering, limit crystal oscillator oscillating at the border of fuzzy area by using CPU control AT cut crystal filter to change filtering bandwidth in order to constantly compress the spectral line width of crystal oscillator. The experiment proves that after taking advantages of the border effect the phase noise and aging ratio get great improvement for the OCXO with two crystal resonators.