Far-field prediction using only magnetic near-field scanning for EMI test

Xu Gao, Jun Fan, Yaojiang Zhang, Hamed Kajbaf, David Pommerenke

Research output: Contribution to journalArticlepeer-review


Far-field prediction for electromagnetic interference (EMI) testing is achieved using only magnetic near-field on a Huygens's surface. The electrical field on the Huygens's surface is calculated from the magnetic near-field using the finite element method (FEM). Two examples are used to verify the proposed method. The first example uses the field radiated by an infinitesimal electric dipole. The calculated results are compared with the analytical solution. In the second example, the calculated results are compared with full-wave simulation results for the radiation of a print circuit board (PCB). The validity of this method when the near-field is high-impedance field is verified as well. Sensitivity of the far field to noise in both magnitude and phase in the near-field data is also investigated. The results indicate that the proposed method is very robust to the random variation of both. The effect of using only four sides of the Huygens's box is investigated as well, revealing that, in some instances, the incomplete Huygens's box can be used to predict the far field well. The proposed method is validated using near-field measurement data taken from a sleeve dipole antenna. The error for the maximum far-field value is in only 1.3 dB.

Original languageEnglish
Article number6819460
Pages (from-to)1335-1343
Number of pages9
JournalIEEE Transactions on Electromagnetic Compatibility
Issue number6
Publication statusPublished - 1 Dec 2014
Externally publishedYes


  • Electromagnetic interference (EMI)
  • equivalence theorem
  • finite element methods (FEMs)
  • magnetic fields
  • near-field-far-field transformation

ASJC Scopus subject areas

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

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