Based On The Design And Realization Of The Integrated Amplifier With Low Phase Noise Crystal Oscillator

It has been nearly a century since the appearance of the first crystal oscillator. During this period, it has been studied and optimized by millions of scientists and researchers. It became more and more popular and its performance continued to be improved. Today, as an excellent signal source, crystal oscillators provide the reference frequency signal for communication and radar systems, becoming the core of the most critical components of communication and radar systems. Its phase noise becomes a major factor which limits the overall performance of these systems. With the increasing requirements to the performance of communications and radars, it is a very important and meaningful work to improve their phase noise performance.This dissertation begins with describing the phase noise as the frequency stability indicator in frequency-domain, and the'Allan variance'indicator in time-domain. Then a series of theoretical formulas are deduced, which transform the phase noise in frequency-domain into the'Allan variance'. Base on it, a kind of practical method for the transformation is given, which is used for analyzing the measurement results in the end. The principle of the oscillator which performs in the way of positive feedback is illustrated. On the base of'Leeson model', the analysis about the relations between the amplifier and the noise of the oscillator is given. And this is proved by a simulation demonstrated with ADS v2008. Later, describing the effect of the Q-value of the resonator, and a series of analysis about how to select the parameters of the amplifier and the resonator and a kind of design ideas for optimizing the phase noise is given. Finally, base on these ideas, an oscillator circuit is done with the MAXIM's integrated amplifier as the output amplification components, and the phase noise measurements are obtained with signal source analyzer Agilent E5052B.