基于数字锁相放大器测量电阻热噪声  

Measuring the resistance thermal noise based on digital lock-in amplifier

作　　者：贾莲莲[1,2] 贺子芸 曾迪昂 王自鑫 蔡志岗[1,2] JIA Lian-lian;HE Zi-yun;ZENG Di-ang;WANG Zi-xin;CAI Zhi-gang(National Level Experiment Teaching Center for Physics,Sun Yat-sen University, Guangzhou 510275, China;School of Electronics and Information Technology,Sun Yat-sen University, Guangzhou 510275, China;School of Physics,Sun Yat-sen University, Guangzhou 510275, China)

机构地区：[1]中山大学物理学国家级实验教学示范中心,广东广州510275 [2]中山大学物理学院,广东广州510275 [3]中山大学电子与信息工程学院,广东广州510275

出　　处：《物理实验》2018年第12期1-5,共5页Physics Experimentation

基　　金：广州市科技计划项目(No.201707010422)

摘　　要：数字式锁相放大器利用相干解调的方法对有用信号进行搬移,再结合高Q值的窄带低通滤波器对搬移后的信号进行低通滤波,最后得到有用信号的幅值与相位信息.利用OE1022锁相放大器测量了电阻热噪声,使用LabVIEW采集电阻热噪声数据,并用MAD算法统计处理数据.实验结果表明:1kΩ～1MΩ的陶瓷电阻的热噪声测量值符合电阻热噪声理论.The coherent demodulation method was used to shift the useful signal of the digital phase-locked amplifier,and then the narrow-band low-pass filter with high Qvalue was used to carry out the low-pass filtering of the shifted signal,finally the amplitude and phase information of the useful signal were obtained.The lock-in amplifier,OE1022,was used to carry out the measurement of resistance thermal noise.The noise was collected with LabVIEW,and then MAD algorithm was used for statistical data processing.The experimental results showed that the thermal noise of ceramic resistor of 1 kΩ ~1 MΩwas in accordance with the theory of resistance thermal noise.

关 键 词：电阻热噪声 锁相放大器 微弱信号 LABVIEW 

分 类 号：TN911.2[电子电信—通信与信息系统] TN722[电子电信—信息与通信工程]