双锁相法在脉冲强磁场弱信号测量中的应用  

Applying of double lock-in technology in the weak signal measurement under pulsed high magnetic field

作　　者：陈子玉[1] 黄彦[1] 曹霞[2] 沈逸宁[1] 王业率[1] 夏念明[1] 左华坤[1] 夏正才[1] 

机构地区：[1]华中科技大学脉冲强磁场中心,武汉430074 [2]湖南工业职业技术学院电气工程系,长沙413000

出　　处：《电子测量技术》2012年第8期27-30,共4页Electronic Measurement Technology

基　　金：中国国家自然科学基金(1104091)

摘　　要：为了解决在脉冲磁场下电输运测量无法使用传统锁相放大器进行弱信号测量的问题,根据锁相原理,设计实现了1套数字锁相系统,并使用LabVIEW软件编写了相应的数据处理程序。通过对信号通过低通滤波器前后波形因为延时而发生的相移的仿真,设计中在还原数据时截去掉与所用低截止频率相关的点数后,可以消除滤波器延时带来的数据误差,使得测量数据很好地还原了原始信号。通过脉冲强磁场下实际样品的电输运测量,证实了所设计的数字锁相系统可以满足脉冲强磁场强干扰环境下弱信号的测量需求。For the problem that the traditional lock-in amplifier cannot perform well in the electrical transfer measurement under pulsed magnetic field,we designed a digital lock-in measurement system referring to the principle of lock-in technology,and also data processing program with in Labview. From the simulation of contrasting the phase displacement of signals due to the time delay of low-pass digital filter, we cut off corresponding points under different lower cut-off frequency while applying the program,the error of time delay is eliminated and the corrected data mostly restoring the original signal. The electrical measurement results of actual sample under pulsed magnetic field confirmed this system meet the demand of weak signal measurement under strong interference environment of pulsed magnetic field.

关 键 词：数字锁相 脉冲磁场 弱信号测量 

分 类 号：TN713.7[电子电信—电路与系统]