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 pro...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.展开更多
Circuit of the temperature measurement equipment was improved in order to develop temperature telemetering system for cultivating fruit facilities.The traditional temperature measuring equipments used in monitoring te...Circuit of the temperature measurement equipment was improved in order to develop temperature telemetering system for cultivating fruit facilities.The traditional temperature measuring equipments used in monitoring temperature changes in greenhouse include mercury column,merbromine column,kerosene column glass rod thermometer and mechanical inductive thermometer.Compared with the traditional method of temperature measurement the new system reduces the labor requirement and promotes precision monitoring and control of the temperature.In addition,the temperature in the greenhouse was very accurate especially at night or in rainy and snowy weather.This new temperature telemetering system will promote the development of the fruit protection cultivation.展开更多
基金Supported by the National Natural Science Foundation of China (10978017)the Open Fund of Key Laboratory of Time and Frequency Primary Standards (CAS)+2 种基金the Postdoctoral Grant of China (94469)the Basic and Advanced Technology Research Foundation of Hennan Province (122300410169)the Fundamental Research Funds for the Central Universities
文摘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.
基金the International S&T Cooperation Project of China(Project No.2012DFR30700)Special Fund for Agro-scientific Research in the Public Interest of China(Project No.200903019)+1 种基金The Ministry of Agriculture 948 Project of China(Project No.2011-Z40)Shandong agricultural improved variety project[No.(2010)6]and Taian scientific and technological development planning item(20075014).
文摘Circuit of the temperature measurement equipment was improved in order to develop temperature telemetering system for cultivating fruit facilities.The traditional temperature measuring equipments used in monitoring temperature changes in greenhouse include mercury column,merbromine column,kerosene column glass rod thermometer and mechanical inductive thermometer.Compared with the traditional method of temperature measurement the new system reduces the labor requirement and promotes precision monitoring and control of the temperature.In addition,the temperature in the greenhouse was very accurate especially at night or in rainy and snowy weather.This new temperature telemetering system will promote the development of the fruit protection cultivation.
