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Fredrik Edman. Fotograf Johan Persson.

Fredrik Edman

Patent advisor

Fredrik Edman. Fotograf Johan Persson.

High precision measurements using high frequency gigahertz signals


  • Aohan Jin
  • Siyuan Fu
  • Atsunori Sakurai
  • Liang Liu
  • Fredrik Edman
  • Tönu Pullerits
  • Viktor Öwall
  • Khadga Jung Karki

Summary, in English

Generalized lock-in amplifiers use digital cavities with Q-factors as high as 5 × 108 to measure signals with very high precision. In this Note, we show that generalized lock-in amplifiers can be used to analyze microwave (giga-hertz) signals with a precision of few tens of hertz. We propose that the physical changes in the medium of propagation can be measured precisely by the ultra-high precision measurement of the signal. We provide evidence to our proposition by verifying the Newton's law of cooling by measuring the effect of change in temperature on the phase and amplitude of the signals propagating through two calibrated cables. The technique could be used to precisely measure different physical properties of the propagation medium, for example, the change in length, resistance, etc. Real time implementation of the technique can open up new methodologies of in situ virtual metrology in material design.


  • Chemical Physics
  • Department of Electrical and Information Technology
  • ELLIIT: the Linköping-Lund initiative on IT and mobile communication

Publishing year





Review of Scientific Instruments





Document type

Journal article


American Institute of Physics (AIP)


  • Electrical Engineering, Electronic Engineering, Information Engineering
  • Atom and Molecular Physics and Optics




  • ISSN: 1089-7623