Effect of Inhomogeneous Medium on Fields above GCPW PCB for Near-Field Scanning Probe Calibration Application

Shubhankar Marathe*, Morten Soerensen, Victor Khilkevich, David Pommerenke, Jin Min, Giorgi Muchaidze

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


In this paper, a method is proposed to calibrate a probe by placing it into a known field and referencing its output voltage to the known field. A transmission line is a convenient structure for creating such a known field. This paper presents the effect of the inhomogeneous medium on the near-field generated over a grounded coplanar waveguide (GCPW) printed circuit board (PCB) and reports the field pattern over the GCPW. GCPW PCBs are used to determine the probe factor for near-field scanning applications. A near-field scan is performed to visualize the near-field sources over a device under test (DUT). The near-field is measured by using E- and H-field electromagnetic interference probes. The output of these probes is a voltage and using the probe factor, the field present over the DUT can be determined. To calculate the probe factor, the near-field strength needs to be known using the 3-D simulation. GCPW creates a quasi-TEM field. The effect of non-TEM modes is easily underestimated, such that non-TEM fields prevent the user from determining the unwanted field suppression of probes at higher frequencies.

Original languageEnglish
Article number8334587
Pages (from-to)3-10
Number of pages8
JournalIEEE Transactions on Electromagnetic Compatibility
Issue number1
Publication statusPublished - 1 Feb 2019
Externally publishedYes


  • E-field probe
  • grounded coplanar waveguide (GCPW)
  • H-field probe
  • near-field scanning
  • probe calibration

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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