Journal of Shandong University(Engineering Science) ›› 2017, Vol. 47 ›› Issue (5): 173-178.doi: 10.6040/j.issn.1672-3961.0.2017.296

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Dual-channel digital lock-in algorithm based on high-modulation frequency

ZHANG Xiaoli, QUAN Wei, LIU Gang   

  1. School of Instrument Science and Opto-Electronics Engineering, Beihang University, Beijing 100191, China
  • Received:2017-02-10 Online:2017-10-20 Published:2017-02-10

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Abstract: In order to increase the maximum modulation frequency of digital lock-in amplifier and detect dual-frequency composite signal simultaneously, a fast digital lock-in algorithm based on square wave reference was proposed. There were four reference signals with frequencies of f and 2f respectively. Two modulation frequencies were set to (2a-1)f and ((4b-2)f respectively, and limited the length of the average filter to avoid interference between the channels. The results of the experiments showed that the proposed algorithm could detect the amplitude and phase of each frequency component of the input signal, and the errors of the amplitudes were less than 0.7% and the errors of the phase were less than 0.5%. It replaced the multiplication by additions and subtractions in the phase-sensitive detection improved the speed of the digital lock-in amplifier and effectively expanded the detection bandwidth of the lock-in amplifier.

Key words: digital lock-in amplifier, dual-channel, modulation frequency, weak signal detection, average filter

CLC Number: 

  • TP206
[1] COVA S, LONGONI A, FREITAS I. Versatile digital lock-in detection technique: application to spectrofluorometry and other fields [J]. The Review of Scientific Instruments, 1979, 50(3):296.
[2] DÍAZ-MICHELENA M, COBOS P, AROCA C. Lock-in amplifiers for AMR sensors[J]. Sensors & Actuators a Physical, 2015, 222(222):149-159.
[3] BARRAGÁN L A, ARTIGAS J I, ALONSO R, et al. A modular, low-cost, digital signal processor-based lock-in card for measuring optical attenuation[J]. Review of Scientific Instruments, 2001, 72(1):247-251.
[4] TONG I O, LEE J W, KIM K S, et al. Digital phase-sensitive demodulator for electrical impedance tomography[J]. International Conference of the IEEE Engineering in Medicine and Biology Society, 2003, 2(2):1070-1072.
[5] 刘文亮, 朱维红, 陈涤,等. 基于雷达图像的运动目标形态检测及跟踪技术[J]. 山东大学学报(工学版), 2010, 40(3):31-36. LIU Wenliang, ZHU Weihong, CHEN Di, et al. Detection and tracking of moving targets using the morphology match in radar images[J]. Journal of Shandong University(Engineering Science), 2010, 40(3):31-36.
[6] ANDERSON M, PERSON L, SEVEVSON T, et al. Flexible lock-in detection system based pm synchronized computer plug-in boards applied in sensitive gas[J]. Review of Scientific Instruments, 2007, 78(11):113107.
[7] 李刚,张丽君,林凌.一种新型数字锁相放大器的设计及其优化算法[J].天津大学学报(自然科学与工程技术版),2008,41(4):429-432. LI Gang, ZHANG Lijun, LIN Ling. Design of a new digital lock-in amplifier and its optimization algorithm[J]. Journal of Tianjin University(Science and Technology), 2008, 41(4):429-432.
[8] LI Gang, ZHOU Mei, HE Feng, et all. A novel algorithm combining oversampling and digital lock-in amplifier of high speed and precision[J]. The Review of scientific instruments, 2011, 82(9): 095106
[9] AYAT M, KARAMI M A, MIRZAKUCHAKI S, et al. Design of multiple modulated frequency lock-in amplifier for tapping-mode atomic force microscopy systems[J]. IEEE Transactions on Instrumentation & Measurement, 2016, 65(10):2284-2292.
[10] KAR A, GOEL P, CHANDRA M, et al. A low-cost, portable alternative for a digital Lock-In amplifier using TMS320C5535 DSP[C] //TENCON 2014-2014 IEEE Region 10 Conference. Bangkok, Thailand: IEEE, 2014:1-5.
[11] SON H H, JUNG I I, HONG N P, et al. Signal detection technique utilizing ‘lock-in’ architecture using 2ωc harmonic frequency for portable sensors[J]. Electronics Letters, 2010, 46(13):891-892.
[12] GASPAR J, CHEN S F, GORDILLO A, et al. Digital lock in amplifier: study, design and development with a digital signal processor [J]. Microprocessors & Microsystems, 2004, 28(4):157-162.
[13] WANG J, WANG Z, JI X, et al. A simplified digital lock-in amplifier for the scanning grating spectrometer [J]. Review of Scientific Instruments, 2017, 88(2):023101.
[14] KUMBHARE P, SARWADE N, SHARMA A K, et al. Simulation of lock in amplifier(LIA)for very low signal measurements[C] //International Conference on Communications and Signal Processing. [S.l.] , IEEE, 2015:1291-1295.
[15] CLARKSON P, ESWARD T J, HARRIS P M, et al. Software simulation of a lock-in amplifier with application to the evaluation of uncertainties in real measuring systems[J]. Measurement Science & Technology, 2010, 21(21):045106.
[16] SCHULTZ K D. Phase-sensitive detection in the undergraduate lab using a low-cost microcontroller[J]. American Journal of Physics, 2015, 84.
[17] 宋楠,隋越,董明,等. 基于虚拟锁相放大器的中红外CO检测系统[J]. 光电子·激光, 2014(12):2343-2349. SONG Nan, SUI Yue, DONG Ming, et al. Amid-infrared carbon oxide detection system based on virtual lock-in amplifier technology [J].Journal of Optoelectronics Laser, 2014(12):2343-2349.
[18] ZHANG S, LI G, LIN L, et al. Optimization of a digital lock-in algorithm with a square-wave reference for frequency-divided multi-channel sensor signal detection[J]. Review of Scientific Instruments, 2016, 87(8):296-488.
[19] LI G, ZHANG S, ZHOU M, et al. A method to remove odd harmonic interferences in square wave reference digital lock-in amplifier[J]. Review of Scientific Instruments, 2013, 84(2):025115.
[20] JIANG G L, YANG H, LI R, et al. A new algorithm for a high-modulation frequency and high-speed digital lock-in amplifier[J]. Measurement Science & Technology, 2016, 27(1):015701.
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