Oven controlled crystal oscillator disciplined based on GPS/BDS receiver
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摘要: 本文研究了一种提高恒温晶振长期稳定性的方法,以GPS/BDS接收机输出的秒脉冲信号为参考信号,校正补偿恒温晶振的频率偏移,在不破坏晶振短期稳定性的前提下,获得更好的长期稳定性. 采用中位值平均滤波和卡尔曼滤波消除相位差的跳变和随机抖动,使用带死区的增量式PID算法控制晶振频率,使其和GPS/BDS接收机输出的秒脉冲信号同步. 测试结果表明:驯服后的晶振和铯钟的钟差峰-峰值不超过47 ns,100 s采样Allan方差为6.22×10−11,10 000 s采样的Allan方差约为1.02×10−12. 证明该驯服方法可以使晶振的长期稳定性得到有效提升,是一种可靠有效的驯服方法.Abstract: A method to improve the long-term stability of crystal oscillator is studied in this paper. The 1 pulse per second signal (1 pps) from GPS/BDS receiver is used as the reference signal to correct and compensate the frequency offset of crystal oscillator, to obtain better long-term stability without destroying the short-term stability of crystal oscillator. Median average filter and Kalman filter are mainly used to eliminate the jump and random jitter of phase. Based on this value, the incremental PID algorithm with dead zone is used to control the crystal oscillator frequency to synchronize with GPS/BDS signal. The test results show that the peak-to-peak value between the crystal oscillator and cesium clock is less than 47 ns, the Allan variance of 100 second sampling is 6.22×10−11, and the Allan variance of 10 000 second sampling is about 1.02×10−12. It is proved that this method can help the crystal oscillator obtain better long-term stability, it is a reliable method.
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Key words:
- disciplined clock /
- Kalman filter /
- PID algorithm /
- crystal oscillator /
- GPS/BDS
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表 1 GPS/BDS接收机输出1 pps与铯钟相位差的Allan方差
采样时间/s 卫星的1 pps与铯钟钟差的Allan方差 晶振和铯钟钟差的Allan方差 1 1.0206×10−8 1.7396×10−10 10 1.0445×10−9 2.6111×10−11 100 1.5567×10−10 6.2165×10−11 1 000 1.7470×10−11 9.1396×10−12 10 000 1.8400×10−12 1.0230×10−12 -
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