摘要
在微处理器系统中,使用数字信号处理技术实现的锁相放大器能显著提升确定小信号的检测能力,提升抗噪声能力同时具有灵活性,常用于各类微弱信号检测仪表中。以音频信号检测为例,基于STM32微处理器设计了数字正交锁相放大器,使用片内12 bit模数转换器获取音频信号,与内部产生的1 kHz参考信号进行正交锁相放大。经测试,系统可测量1μV峰-峰值微弱信号,幅度测量误差小于5%,角度误差小于1%,加入噪声(10倍有效信号幅度)后,幅度测量误差小于10%。此数字正交锁相放大器占用资源少、运算速度快,具有较高准确性。
In microprocessor systems,lock-in amplifier implemented using digital signal processing(DSP)technology can significantly improve the detection ability to determine small signals,improve noise immunity while being flexible.Hence,itis commonly used in various types of weak signal detection instruments.In this paper,we design a digital quadrature lock-in amplifier based on the STM32 microprocessor and use an audio signal as a detection example.It uses an on-chip 12-bit analog-to-digital converter to acquire audio signals and amplifies them in quadrature lock-in with an internally generated 1 kHz reference signal.The system has been tested and verified to measure weak signals of 1μV p-p.The amplitude measurement error isless than 5%,and angle error isless than 1%.The amplitude measurement error isless than 10%after adding noise(10 times the effective signal amplitude).This digital quadrature lock-in amplifier occupies less resources,has fast operation speed,and has high accuracy.
作者
李胜铭
苏子粱
吴振宇
卢湖川
LI Shengming;SU Ziliang;WU Zhenyu;LU Huchuan(School of Innovation and Entrepreneurship,Dalian University of Technology,Dalian 116024,Liaoning,China)
出处
《实验室研究与探索》
CAS
北大核心
2022年第4期88-93,共6页
Research and Exploration In Laboratory
基金
2021年度辽宁省普通高等教育本科教学改革研究一般项目(74)。
