Optimizing measurement SNR for weak near-field scanning applications

Li Guan, Giorgi Maghlakelidze, Xin Yan, Satyajeet Shinde, David Pommerenke

Research output: Chapter in Book/Report/Conference proceedingConference paperpeer-review


Conventional near-field scanning techniques often employ a general setup such as: broadband near-field probe output connected to a chain of amplifiers through a coaxial cable to a spectrum analyzer. In this paper, we investigated how the signal to noise ratio is influenced by the coaxial connection between the probe output and the first amplifier, types of probes, cooling the probes with liquid nitrogen and the amplifier's noise figure. Eliminating cabling between probe and first amplifier, and using a low noise amplifiers helped increase signal-to-noise ratio by ~10dB. Further, liquid nitrogen is used to cool down a tunable resonant probe. This increases quality factor of the resonance and improves sensitivity. Thus, SNR is further improved by 10-12dB compared to a similar broadband setup.

Original languageEnglish
Title of host publication2017 IEEE International Symposium on Electromagnetic Compatibility, Signal and Power Integrity, EMCSI 2017 - Proceedings
PublisherInstitute of Electrical and Electronics Engineers
Number of pages5
ISBN (Electronic)9781538622308
Publication statusPublished - 20 Oct 2017
Externally publishedYes
Event2017 IEEE International Symposium on Electromagnetic Compatibility and Signal/Power Integrity: EMCSI 2017 - Washington, United States
Duration: 7 Aug 201711 Aug 2017

Publication series

NameIEEE International Symposium on Electromagnetic Compatibility
ISSN (Print)1077-4076
ISSN (Electronic)2158-1118


Conference2017 IEEE International Symposium on Electromagnetic Compatibility and Signal/Power Integrity
Country/TerritoryUnited States


  • EMI
  • GPS
  • GSM
  • liquid nitrogen
  • magnetic field measurement
  • near field scanning
  • probe
  • probe cooling
  • resonant probes
  • SNR

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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