Delicate Design And Study Of OCXO With Excellent Performance

Oven controlled crystal oscillators (OCXO) as a type of crystal oscillators with highest frequency stability are widely used in measuring instruments, navigation, radar, mobile communication, programmed telephone, audio-visual equipment etc. The thesis is aimed to research and design a novel OCXO with small size, high stability and good start-up characteristic based on single oven structure through delicate designing of the oscillating circuit, temperature control circuit and the oven structure. The main content of the thesis is as follows: The basic theory of design of OCXO has been summarized, including the design of oscillator circuit and temperature control circuit. According to the basic theory of crystal oscillator circuit high frequency stability oscillating circuit is designed. A temperature control circuit that uses the Atmega8 microprocessor to control temperature is designed. The influence of the topology and parameter of temperature measure circuit on the accuracy of measuring temperature and the frequency stability of OCXO is analyzed thoroughly. The importance of the startup characteristic of OCXO is discussed and some solutions are suggested to improve the startup characteristic of OCXO. A system of auto-debugging of the characteristics of OCXO is designed to shorten design period and cut down the cost of OCXO.