Demodulation Techniques for Self-Oscillating Eddy-Current Displacement Sensor Interfaces: A Review

Vikram Chaturvedi, Mohammad Reza Nabavi, Johan G. Vogel, Stoyan Nihtianov

Research output: Contribution to journalArticleScientificpeer-review

19 Citations (Scopus)


This paper presents a comprehensive study of demodulation techniques for high-frequency self-oscillating eddy-current displacement sensor (ECDS) interfaces. Increasing the excitation frequency is essential for lowering the skin depth in many demanding industrial applications, that require better resolution. However, a high excitation frequency poses design challenges in the readout electronics, and particularly in the demodulation functional block. We analyze noise, linearity, and stability design considerations in amplitude demodulators for nanometer and sub-nanometer ECDSs. A number of state-of-the-art amplitude demodulation techniques employed in high-frequency ECDSs are reviewed, and their pros and cons are evaluated.
Original languageEnglish
Pages (from-to)2617-2624
Number of pages8
JournalIEEE Sensors Journal
Issue number9
Publication statusPublished - 2017


  • displacement measurement
  • ECDS interface
  • amplitude demodulation technique

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