Development Of Ultra Low Power OCXO

Aiming at the research on low power consumption technology of Oven Controlled Crystal Oscillator(OCXO),a low power OCXO was developed in this paper in order to solve the problem of insufficient domestic supply capacity.Through the power consumption analysis of each part of OCXO,a low-power OCXO structure based on self-heating crystal resonator technology was developed.This structure realizeed the integration of resonance,heating,and temperature sensing,which improved the effectiveness of heat transfer,and reduced heat loss by effective thermal insulation design,thus reduced the power consumption of OCXO.In order to solve the thermal stress problem of the self-heating crystal resonator,the blank used double-angle SC cut design.By corrected the arm angle of the X-ray tube and the receiver tube of the single-angle-cut angle measurement system and introduced the concept of peak spacing,the problem of the machining accuracy of the arm and measuring the angle of the SC-cut blank were solved.This angle measurement system was confirmed by temperature test of the resonator corresponding to blank angle.The Cr20Ni80 alloy film with precise proportion had obtained through using alloy target coating process,and modification of the vacuum system,the Ar flow control system,the cooling cycle system of the magnetron sputtering coating equipment.After that,the self-heating crystal resonator's film was finished,also with the study on annealing process.The resistance of the heating electrode film was 15-20?,the result meet the design requiremt.We solved the problem with the placement of temperature-sensing devices,and realized no time delay measurement of quartz blank's temperature through the development of the multi-contact low-leakage cold-pressure welding base.Through B-mode frequency verification,the temperature measurement accuracy is 0.2?,so this method can achieve more accurate temperature measurement and less power fluctuation.Thermal insulation device was designed with small thermal conductivity material,which can directly insulate the self-heating crystal resonator.This reduced the thermal loss of the resonator greatly.The calculated equivalent power of heat transfer was about 0.0312 W,which greatly reduced the power consumption of the temperature control circuit.After thess experiments,samples were obtained by make self-heating crystal resonators,assemble thermal insulation components,match oscillation circuit and output circuits etc.The sample's startup power was less than 1W,standby power less than 100 mW,startup time less than 120 S,which can meet the requirements of the subject.The phase noise is consistent with the conventional OCXO,and the aging per day is better than 0.1ppb,so other parameters of this type of products were not affected during process.The low-power OCXO based on self-heating crystal resonator technology meeted the design requirements and reached the international level.