New design of high-precision oven controlled crystal oscillator

Combining oven controlled technique, digital compensation, high-resolution frequency difference measurement and self-calibration technique, a new design method of precise oven controlled crystal oscillator (OCXO) is proposed. Fine compensation is made in the vicinity of the crystal temperature inflection point by using the non-real-time temperature compensation strategy, and self-calibration system is integrated in the crystal. The method improves the digital compensated phase noise, simplifies the traditional OCXO development system, reduces the cost and shortens the developing cycle. Experiment results show that with a standard reference signal and self-calibration updated data, the oscillator can work stable and achieve its best performence. The performance index of crystal oscillator had an improvement with one to two orders of magnitude on the basis of original technical index. The method is widely used in the improvement of high-end crystal oscillator and atomic clock.