小型化微处理机温度补偿晶体振荡器的研究
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摘要
随着电子技术的飞速发展,频率高度稳定的晶体振荡器得到了广泛的应用,特别是温度补偿晶体振荡器(TCXO)更是广泛应用于通信、导航、雷达、测量仪表等电子设备中。
在TCXO中,微处理机温度补偿晶体振荡器(MTCXO)是一种比较新型的数字式温度补偿晶体振荡器。本文研究了一种小型化微处理机温度补偿晶体振荡器。首先对石英晶体谐振器的频温特性进行分析,然后通过求解描述固体中弹性声波的Christoffel方程,得到其在切角Φ3 =0 ,Φ1=35 6′处也即AT切石英晶体谐振器的频率温度特性曲线,这是本文进行温度补偿的理论依据。并由此设计了振荡电路的实际电路。接着分析了MTCXO的温度补偿原理,介绍了系统的基本结构及工作原理,器件选择和电路设计,以及微处理器ADμC814的在线调试系统。之后文章详述了单片机的软件程序设计。
由于微处理器ADμC814功能强大,内部集成了温度传感器、ADC、DAC和CPU等部分,使得系统可以充分发挥软件的优势。在设计中采用软件以及软硬相结合的方法代替大量的硬件电路,这样就大大减少了晶体振荡器的体积及制造成本。
最后进行实验,通过对实验数据的分析,本文提出了一种改进方案,即采用外部温度传感器DS18B20,避免内部传感器的精度不高及干扰带来的误差,能在一定程度上改善系统输出频率。
With the quick development of electronic technology, high-stability crystal oscillator is being used more and more widely. Especially, temperature-compensated crystal oscillator (TCXO) is commonly used in electronic equipments such as communication, navigation, radar, measure instruments etc..
Therein, microprocessor temperature compensation crystal oscillator (MTCXO) is a comparatively new-type digital compensated crystal oscillator. In this paper, a type of miniature microcomputer compensated crystal oscillator is studied. First, the frequency-temperature (F-T) characteristic of quartz crystal resonator is analyzed. Then, the frequency-temperature (F-T) characteristic curve of AT-cut quartz crystal resonator (at cut angle:Φ3 =0 ,Φ1=35 6′) is obtained based on analyzing the Christoffel equation describing flexibility sound wave in solids, which serves as the theory basis used for temperature compensated, from which the actual circuit of oscillatory circuit is designed. Moreover, the compensation principles of MTCXO are dicussed, and the basic structure and operating principles of the system are introduced systematically. Forethermore, MCU software design is presented detailedly.
This powerful microprocessor ADμC814 integrates temperature sensor, ADC, DAC, and MCU, so that it lets the system make full use of the software. In the process of design, a method, which combines the software with the hardware, is used to replace a large number of hardware circuits. Hence, it is beneficial for greatly reducing the size and manufacturing costs of crystal oscillators.
Finally, based on the analysis of the experiment results, an improved scheme is put forward, that is, the application of the external temperature sensor DS18B20, which avoids the error caused by low precision of the internal sensor and interference and improves system output frequency to some degree.
在TCXO中,微处理机温度补偿晶体振荡器(MTCXO)是一种比较新型的数字式温度补偿晶体振荡器。本文研究了一种小型化微处理机温度补偿晶体振荡器。首先对石英晶体谐振器的频温特性进行分析,然后通过求解描述固体中弹性声波的Christoffel方程,得到其在切角Φ3 =0 ,Φ1=35 6′处也即AT切石英晶体谐振器的频率温度特性曲线,这是本文进行温度补偿的理论依据。并由此设计了振荡电路的实际电路。接着分析了MTCXO的温度补偿原理,介绍了系统的基本结构及工作原理,器件选择和电路设计,以及微处理器ADμC814的在线调试系统。之后文章详述了单片机的软件程序设计。
由于微处理器ADμC814功能强大,内部集成了温度传感器、ADC、DAC和CPU等部分,使得系统可以充分发挥软件的优势。在设计中采用软件以及软硬相结合的方法代替大量的硬件电路,这样就大大减少了晶体振荡器的体积及制造成本。
最后进行实验,通过对实验数据的分析,本文提出了一种改进方案,即采用外部温度传感器DS18B20,避免内部传感器的精度不高及干扰带来的误差,能在一定程度上改善系统输出频率。
With the quick development of electronic technology, high-stability crystal oscillator is being used more and more widely. Especially, temperature-compensated crystal oscillator (TCXO) is commonly used in electronic equipments such as communication, navigation, radar, measure instruments etc..
Therein, microprocessor temperature compensation crystal oscillator (MTCXO) is a comparatively new-type digital compensated crystal oscillator. In this paper, a type of miniature microcomputer compensated crystal oscillator is studied. First, the frequency-temperature (F-T) characteristic of quartz crystal resonator is analyzed. Then, the frequency-temperature (F-T) characteristic curve of AT-cut quartz crystal resonator (at cut angle:Φ3 =0 ,Φ1=35 6′) is obtained based on analyzing the Christoffel equation describing flexibility sound wave in solids, which serves as the theory basis used for temperature compensated, from which the actual circuit of oscillatory circuit is designed. Moreover, the compensation principles of MTCXO are dicussed, and the basic structure and operating principles of the system are introduced systematically. Forethermore, MCU software design is presented detailedly.
This powerful microprocessor ADμC814 integrates temperature sensor, ADC, DAC, and MCU, so that it lets the system make full use of the software. In the process of design, a method, which combines the software with the hardware, is used to replace a large number of hardware circuits. Hence, it is beneficial for greatly reducing the size and manufacturing costs of crystal oscillators.
Finally, based on the analysis of the experiment results, an improved scheme is put forward, that is, the application of the external temperature sensor DS18B20, which avoids the error caused by low precision of the internal sensor and interference and improves system output frequency to some degree.
引文
[1] 荆震.高稳定晶体振荡器.北京:国防工业出版社,1975,12-24
[2] 程天军.晶体振荡器国内外动态与预测.陕西省频率控制与测量技术论文集 1991,(No.1):14-26
[3] 高景浩,陈国胜.石英晶体振荡器动态.压电晶体技术,1988(2):45-56
[4] 赵声衡.石英晶体振荡器.长沙:湖南大学出版社,1997
[5] 吴培才,刘进忙,胡国平.温度补偿晶体振荡器.北京:国防工业出版社,1994,42-63
[6] 张建国.愈做愈小的片式化温补晶振.元器件与应用,2003.2,25-33
[7] 秦自楷,等编.压电石英晶体.北京:国防工业出版社,1980,56-67
[8] 张肃文,陆兆熊.高频电子线路.北京:高等教育出版社,1993,48-51
[9] 陈振国.微波技术基础与应用.北京:北京邮电大学出版社,2002,28-34
[10] 黄显核,陈志远.双旋 Y 切石英振子 T 模的分析和 SC 切双模振荡器的研究.电讯技术,1989,Vol.29,No.2
[11] Huang Xianhe, Sun Xinghong, Wang feng, etc. A Research on the F-T Characteristic of Thickness Mode of Dual Rotated Y-cut Piezoelectric Quartz Crystal. Proceedings of the Symposium on Smart Materials for Engineering and Biomedical Applications. Beijing:China Aviation Industry Press,2004,93-98
[12] Matthys, Robert J. Crystal oscillator circuits. New York: Wiley, 1983,12:134-148
[13] Frerking, Marvin E. Crystal oscillator design and temperature compensation. New York: Rinhold, 1978,23:211-224
[14] Fairweather, D. Quartz crystals as oscillators and resonators. New York: Marconi's Wireless Telegraph Co., 1970,13:88-95
[15] 李刚.AduC8XX 系列单片机原理与应用技术.北京:北京航空航天大学出版社,2002,55-63
[16] 李广军,王厚军.实用接口技术.成都:电子科技大学出版社,1998,64-69
[17] 王华,等编.Matlab 在电信工程中的应用.北京:中国水利水电出版社,2001,131-142
[18] 周明德.微型计算机系统原理及应用(第三版)上册.北京:清华大学出版社,1998
[19] 江思敏,姚鹏翼,胡荣,等编.Protel 电路设计教程.北京:清华大学出版社,2002
[20] MinQiang Li, XianHe Huang etc. A Novel Microcomputer Temperature-Compensating Methodfor an Overtone Crystal Oscillator. IEEE Transacions On Ultrasonics, Ferroelectrics, And Frequecy Control, November 2005, Vol.52, No.11,1919-1922
[21] 黄显核,黎敏强,付玮,谭峰.一种石英晶体振荡器温度补偿方法.中国专利,申请号:CN200410022680.3,公开号:CN1705222
[22] 赵生双,赵焕绥,王玉国,等.一种新型的温度补偿晶体振荡器.JOURNAL OF SHANDONG UNIVERSITY,Sept.1997,Vol.32 No.3
[23] Zhou Wei. Systematic Reseach on High-Accuracy Frequency Measurements and Control: Doctor dissertation. Japan: Shizuoka University. Feb., 2000
[24] Jacquet E, Pardon J-P, Bignon O. Digitally compensated TCXO with low phase noise characteristics. Proceedings of the IEEE International Frequency Control Symposium, 1999,Volume: 1,13-16 April 1999,370-375
[25] Nakazawa M, Yamamoto F, Imari T. Frequency jump characteristics versus temperature changes in AT cut bar oscillators. Proceedings of the IEEE International Frequency Control Symposium, 1999, Volume:1,13-16 April 1999,34-350
[26] Brendel R, Marianneau G, Blin T etc. Computer aided design of quartz crystal oscillators. Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, Volume: 42, Issue: 4,July 1995,700-708
[2] 程天军.晶体振荡器国内外动态与预测.陕西省频率控制与测量技术论文集 1991,(No.1):14-26
[3] 高景浩,陈国胜.石英晶体振荡器动态.压电晶体技术,1988(2):45-56
[4] 赵声衡.石英晶体振荡器.长沙:湖南大学出版社,1997
[5] 吴培才,刘进忙,胡国平.温度补偿晶体振荡器.北京:国防工业出版社,1994,42-63
[6] 张建国.愈做愈小的片式化温补晶振.元器件与应用,2003.2,25-33
[7] 秦自楷,等编.压电石英晶体.北京:国防工业出版社,1980,56-67
[8] 张肃文,陆兆熊.高频电子线路.北京:高等教育出版社,1993,48-51
[9] 陈振国.微波技术基础与应用.北京:北京邮电大学出版社,2002,28-34
[10] 黄显核,陈志远.双旋 Y 切石英振子 T 模的分析和 SC 切双模振荡器的研究.电讯技术,1989,Vol.29,No.2
[11] Huang Xianhe, Sun Xinghong, Wang feng, etc. A Research on the F-T Characteristic of Thickness Mode of Dual Rotated Y-cut Piezoelectric Quartz Crystal. Proceedings of the Symposium on Smart Materials for Engineering and Biomedical Applications. Beijing:China Aviation Industry Press,2004,93-98
[12] Matthys, Robert J. Crystal oscillator circuits. New York: Wiley, 1983,12:134-148
[13] Frerking, Marvin E. Crystal oscillator design and temperature compensation. New York: Rinhold, 1978,23:211-224
[14] Fairweather, D. Quartz crystals as oscillators and resonators. New York: Marconi's Wireless Telegraph Co., 1970,13:88-95
[15] 李刚.AduC8XX 系列单片机原理与应用技术.北京:北京航空航天大学出版社,2002,55-63
[16] 李广军,王厚军.实用接口技术.成都:电子科技大学出版社,1998,64-69
[17] 王华,等编.Matlab 在电信工程中的应用.北京:中国水利水电出版社,2001,131-142
[18] 周明德.微型计算机系统原理及应用(第三版)上册.北京:清华大学出版社,1998
[19] 江思敏,姚鹏翼,胡荣,等编.Protel 电路设计教程.北京:清华大学出版社,2002
[20] MinQiang Li, XianHe Huang etc. A Novel Microcomputer Temperature-Compensating Methodfor an Overtone Crystal Oscillator. IEEE Transacions On Ultrasonics, Ferroelectrics, And Frequecy Control, November 2005, Vol.52, No.11,1919-1922
[21] 黄显核,黎敏强,付玮,谭峰.一种石英晶体振荡器温度补偿方法.中国专利,申请号:CN200410022680.3,公开号:CN1705222
[22] 赵生双,赵焕绥,王玉国,等.一种新型的温度补偿晶体振荡器.JOURNAL OF SHANDONG UNIVERSITY,Sept.1997,Vol.32 No.3
[23] Zhou Wei. Systematic Reseach on High-Accuracy Frequency Measurements and Control: Doctor dissertation. Japan: Shizuoka University. Feb., 2000
[24] Jacquet E, Pardon J-P, Bignon O. Digitally compensated TCXO with low phase noise characteristics. Proceedings of the IEEE International Frequency Control Symposium, 1999,Volume: 1,13-16 April 1999,370-375
[25] Nakazawa M, Yamamoto F, Imari T. Frequency jump characteristics versus temperature changes in AT cut bar oscillators. Proceedings of the IEEE International Frequency Control Symposium, 1999, Volume:1,13-16 April 1999,34-350
[26] Brendel R, Marianneau G, Blin T etc. Computer aided design of quartz crystal oscillators. Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, Volume: 42, Issue: 4,July 1995,700-708