基于计算机声卡的双相数字锁定放大器系统  

Digital Dual-Phase Lock-in Amplifier System Based on a Computer Sound Card

作　　者：陶冶博 沈旭东 吴湘莲[1] 秦国栋[1] 杨嘉怡 TAO Yebo;SHEN Xudong;WU Xianglian;QIN Guodong;YANG Jiayi(College of Intelligent Manufacturing,Jiaxing Vocational&Technical College,Jiaxing Zhejiang 314036,China;College of Computer Science and Technology,Xi’an University of Science and Technology,Xi’an Shaanxi 710054,China)

机构地区：[1]嘉兴职业技术学院智能制造学院,浙江嘉兴314036 [2]西安科技大学计算机科学与技术学院,陕西西安710054

出　　处：《电子器件》2023年第2期314-320,共7页Chinese Journal of Electron Devices

基　　金：国家自然科学基金项目(62101432);2021年浙江省教育厅一般科研项目(Y202146138);2021年嘉兴市公益性研究计划项目(2021AY10052);2022年度浙江省高校访问工程师校企合作项目(FG2022314);嘉兴职业技术学院2023年校立科研项目(jzyy202316)。

摘　　要：锁定放大器是一种微弱信号检测设备,被广泛应用于化学、生物医学等领域。然而,现有锁定放大器存在体积大、价格昂贵以及定制化难度大的问题。为了解决以上问题,提出了一种基于计算机声卡的双相数字锁定放大器系统。该双相数字锁定放大器由计算机声卡、前置低噪声放大器与基于MATLAB GUI的软件算法构成,只保留前置低噪声放大器模拟电路,其余算法均采用软件实现,能够减小系统体积,降低成本,并可以通过MATLAB快速实现定制化。实验表明当积分时间为2 s时,该双相锁定放大器测量低频(100 Hz~10 k Hz)、低信噪比(>-18.9 d B)正余弦信号幅度的相对误差小于4.6%。Lock-in amplifier is a weak signal detection device,which is widely used in chemical,biomedical and other fields.However,the existing lock-in amplifier has the problems of large size,high price and difficult customization.To solve the above problems,a digital dual-phase lock-in amplifier system based on computer sound card is presented.The digital dual-phase lock-in amplifier consists of a computer sound card,a low noise preamplifier and a software algorithm based on MATLAB GUI.Only the low noise preamplifier analog circuit is retained,and other algorithms are implemented by software,which can reduce the volume of the system,lower the costs,and quickly realize customization through MATLAB.Experiments show that when the integration time is 2 s,the relative error of the dual-phase lock-in amplifier in measuring the amplitude of sine and cosine signals with low frequency(100 Hz-10 kHz)and low signal-to-noise ratio(>-18.9 dB)is less than 4.6%.

关 键 词：微弱信号检测 锁定放大器 低噪声放大器 信噪比 误差校正 

分 类 号：TN722[电子电信—电路与系统]