A Coil-Shaped Near-Field Probe Design for EMI Applications

Chi-Yuan YAO  Wen-Jiao LIAO  

IEICE TRANSACTIONS on Communications   Vol.E102-B   No.2   pp.337-344
Publication Date: 2019/02/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2018EBP3107
Type of Manuscript: PAPER
Category: Electromagnetic Compatibility(EMC)
electromagnetic interference,  near-field probes,  current-induced field,  capacitive coupling,  

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Coil-shaped structures are proposed to enhance sensitivity and spatial resolution for EMI near-field probe. This design yields a high sensitivity and a good spatial resolution to find the EMI source in near-field region. Both characteristics are crucial to diagnosis of emissions from electrical and electronic devices. The new design yields a superior sensitivity, which is in general 15 dB greater than conventional probes. This new probe helps practitioners to quickly and correctly locate noise emission source areas on printed circuit boards and devices. Two prototypes of different sizes were fabricated. The larger one provides a high sensitivity while the smaller one can pinpoint emission source locations. The new probe design also has an orientation invariance feature. Its noise response levels are similar for all probe directions. This characteristic can help reduced the probability at miss-detection since sensitivity is largely invariant to its orientation. Extensive measurements were performed to verify the operation mechanism and to assess probe characteristics. It suits well to the electromagnetic interference problem diagnosis.