摘要
为了从强噪声背景中提取出与磁场大小相关的微弱磁测信号,研究基于正交矢量全数字锁相放大器的全数字弱磁信号检测系统。以软件编程代替传统的模拟锁相放大器,调试简单,集成度高。采用直接数字频率合成技术在数字域生成正交参考信号,降低相敏检波误差。通过频率控制字控制输出信号的频率,输出范围更大且稳定性好。由频率控制字直接解算得到射频驱动信号频率,避免了测频电路引入的测频误差,有效提高磁力仪的精度。结果表明,该全数字锁相放大器幅值测量误差为0.0736 V,相位测量误差为0.0644°,满足Mx型铯光泵磁力仪信号检测系统的检测要求。相对于模拟锁相放大器,全数字锁相放大器能够有效改善相位提取精度。
To extract the weak magnetic signal from strong noise background,a full digital weak magnetic signal detection system is proposed based on the orthogonal vector full digital lock-in amplifier.This method replaces the traditional analog lock-in amplifier with software programming,offering easy debugging and high integration.By employing direct digital frequency synthesis technology,orthogonal reference signals are generated in the digital domain,which reduces the error of phase sensitive detection.The frequency of the radio frequency drive signal is directly calculated from the frequency control word,which avoids the frequency measurement error introduced by the frequency measurement circuit and effectively improves the accuracy of the magnetometer.Experimental results show that the amplitude measurement error of this fully digital lock-in amplifier is 0.0736 V,and the phase measurement error is 0.0644°,meeting the detection requirements for the Mx-type cesium optical pumping magnetometer signal detection system.Compared to analog lock-in amplifiers,the fully digital lock-in amplifier can significantly improve phase extraction accuracy.
作者
杨颖
刘翔
YANG Ying;LIU Xiang(School of Automation and Electrical Engineering,Tianjin University of Technology and Education,Tianjin 300222,China)
出处
《天津职业技术师范大学学报》
2025年第1期7-11,18,共6页
Journal of Tianjin University of Technology and Education
基金
天津市教委科研计划项目(2022KJ115).
关键词
光泵磁力仪
锁相放大器
弱磁检测
正交矢量型相敏检波
optical pumping magnetometer
lock-in amplifier
weak magnetic detection
orthogonal vector phase sensitive detection
