Property of Butterworth Type Low-Pass Filter Used in Lock-in Amplifier for Precise Capacitance Transducer

  • Yu Huang
  • Li-Hua Wu
Conference paper
Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 238)


Based on the fact that Op Amps of Butterworth low-pass filter is non-ideal, the transfer function of VCVS type two-order Butterworth LPF based on non-ideal Amps is deduced theoretically. The influence of non-ideal characteristic on filter is studied, and the relationship between step response and control time of filter based on non-ideal Amps and periphery circuit parameters is analyzed and calculated. The effect of LPF with non-ideal Amps on real-time of tiltmeter is evaluated. The control time and cutoff frequency of LPF are tested by experiment and the results are basically in accord with the theoretical ones.


Control Time Step Response Output Impedance Circuit Parameter Ideal Filter 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This work was supported by the National Nature Science Foundation of China under Grant Nos. 61004130 and the Fundamental Research Funds for the Central Universities under Grant Nos. HUECFL20111107.


  1. 1.
    Huang Y, Wu LH (2007) Crustal tilt measurement with two-dimension vertical pendulum tiltmeter. Chin J Scientific Instrum 28(8):1514–1517Google Scholar
  2. 2.
    Martínez O, Carvajal MA, Morales DP et al (2008) Development of an electrical capacitance tomography system using four rotating electrodes. Sens Actuators A 148:366–375Google Scholar
  3. 3.
    Yang WQ, Stott AL, Xie CG et al (1995) Development of capacitance tomographic imaging systems for oil pipeline measurements. Rev Sci Instrum 66:4326–4332CrossRefGoogle Scholar
  4. 4.
    Trevor Y, Sun LL, Chris G et al (2004) Silicon-based miniature sensor for electrical tomography. Sens Actuators A 110:213–218Google Scholar
  5. 5.
    Mwambela AJ, Johansen GA (2001) Multiphase flow component volume fraction measurement experimental evaluation of entropic threshold methods using an electrical capacitance tomography system. Meas Sci Technol 12:1092–1101CrossRefGoogle Scholar
  6. 6.
    Cui ZQ, Wang HQ (2010) Improvements on real-time performance of electrical capacitance tomography. Chin J Scientific Instrum 31(9):1939–1945Google Scholar
  7. 7.
    Gamio JC, Yang WQ, Stott AL (2001) Analysis of non-ideal characteristics of an ac-based capacitance transducer for tomography. Meas Sci Technol 12:1076–1082CrossRefGoogle Scholar
  8. 8.
    Wang BL, Ji HF, Huang ZY et al (2005) A high speed data acquisition system for ECT based on the differential sampling method. IEEE Sens J 5(2):308–312CrossRefGoogle Scholar
  9. 9.
    Gualtieri DM (1987) Precision of lock-in amplifier as a function of signal-to-noise ratio. Rev Sci Instrum 58:299–300CrossRefGoogle Scholar
  10. 10.
    Zhu XM, Wang HQ, Zhang LF (2004) The effect of low-pass filter on the real-time performance of ECT system. Chin J Scientific Instrum 25(6):816–819Google Scholar
  11. 11.
    Wang HQ, Cao Z (2005) Optimization of low pass filter design in lock-in amplifier. Chin J Scientific Instrum 26(7):684–688; 704Google Scholar
  12. 12.
    Abraham M (1982) Design of Butterworth-type transimpedance and bootstrap-transimpedance preamplifiers for fiber-optic receivers. IEEE Trans Circuits Syst 29:375–382CrossRefGoogle Scholar
  13. 13.
    Huang Y (2008) Experimental study and analysis on noise of mini-displacement capacitance sensor circuit. Chin J Sens Actuators 21(10):1713–1716Google Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.College of scienceHarbin Engineering UniversityHarbinChina

Personalised recommendations