摘要
目前几乎所有的温度补偿晶体振荡器都通过补偿电路来完成补偿,而且采用的是基频晶体.通过长期对石英晶体不同的物理特征相结合的研究,如其频率温度特性和频率应力特性结合,发现通过随温度变化产生的应力来补偿温度本身对晶体频率的影响往往会取得更好的效果.大量实验证明通过应力处理,泛音晶体的频率温度特性得到明显的改善.使用这种方式,晶体振荡器显示了良好的频率温度特性和短期稳定度,并兼有低功耗、低成本、低相位噪声等优点.振荡器的频率温度稳定度从-30℃到＋85℃的波动范围已经可以达到±（1～2）×10^-6.再通过简单的补偿电路会得到±0.5×10^-6的频率-温度稳定度.对泛音晶体电极采用双层镀膜的方法,使用2种金属镀膜电极产生合适的应力.这相当于是一个双金属温度传感器,当温度改变时,传感器会发生相应的形变,从而该电极可以将应力加于晶体片.这里选择的泛音晶体比基频晶体在稳定度和老化方面要更好一些,而且拥有更高的频率-应力灵敏度.
Currently, almost all temperature compensated crystal oscillators are compensated using compensation circuit and are based on fundamental frequency crystal. Through long-term research on the combination of different physical characteristics of quartz crystal, such as the combination of frequency-temperature characteristic and frequency-stress characteristic, we found that using the generated stress varying with temperature to compensate for the effect of temperature on crystal frequency tends to get better result. A large amount of experiments prove that with stress processing, the frequency-temperature performance of overtone crystals can be improved obviously. In this way, the crystal oscillators exhibit better frequency-temperature performance and short term stability, and also possess the advantages of lower power consumption, lower cost, lower phase noise, and etc. The frequency-temperature stability of the oscillators is improved to ± 1 -2 × 10^-6 in the temperature variation range from -30℃ to ＋ 85 ℃. With some simple additional circuit compensation it is easy to obtain the frequency-temperature stability of ± 0.5 × 10 ^-6. The double plating method is used on the overtone crystal electrodes and makes the two plating electrodes generate suitable stress, which is equivalent to a double metal temperature sensor; and when the temperature changes, the sensor generates strain accordingly, hence applies stress to the crystal. In the study, the overtone crystal is selected, which displays better stability, aging property and higher frequency-stress sensitivity than fundamental crystal.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2014年第7期1594-1599,共6页
Chinese Journal of Scientific Instrument
基金
西安市科技计划(CXY1351(6))
中国科学院精密导航定位与定时技术重点实验室基金(2012PNTT05)
宇航动力学国家重点实验室开放基金(2013ADL-DW0402)
国家自然科学基金(61201288
10978017)资金项目
