The Design Of High-stability Oven Crystal Oscillator

The high-stability Oven Crystal X-tal Oscillator is one of the most significance frequency supplies. Because of its high stability, and good aging characteristics, the OCXOs are widely used in telecommunications equipment, radar, navigation etc.Based on die bonding technology, this paper presents a design of high-stability OCXO. First of all, the basic principles and theories of the quartz crystal resonators and oscillators were discoursed and explicated. Secondly, the paper has summarized and classified the design methods of thermostat bath and has done a thorough theoretical study on phase noise in oscillator design, Lesson oscillator model and a variety circuit of oscillator. Thirdly, this paper designed a circuit of OCXO, calculated the parameters of its main components, and described the function and the role of its key components in detail. The experiment has improved the overall circuit design to achieve the aging rate, adjustable scope of the intended specifications. The aging rate, adjustable range and other indicators had improved though experiments. Some of these improvements,is very useful to improve the circuit performance.Then, in order to further reduce the environmental impact of temperature on the oscillator, temperature control circuits and thermostat bath had designed for this project. Finally, the PCB had been designed and the model of OCXO had been producedThe results of test showed that the Frequency stability of the OCXO can reach 10-8 magnitude, phase noise can reach-130 dBc/Hz, the Volume is smaller (35×35×13mm3), the aging is lower (3.9×10-9MHz/d), it has low power consumption (the starting current of 400mA, steady current of 90mA) and has good temperature characteristics (10-8 orders of magnitude), etc. So it was an ideal oven crystal oscillator.