Scalar Matching Indexes for Broadband EM Noise Source Determination With One-Port Measurements

The determination of noise sources of radiated electromagnetic noise is the first task that needs to be addressed when an electromagnetic compatibility (EMC) problem appears. Broadband noise sources are more difficult to identify, particularly when similar switching frequencies are used by different sources. Four techniques for the fast determination of broadband electromagnetic noise sources in complex equipment are proposed. All the four techniques make use of one-port measurements conducted in near and far field in different time instants, avoiding unwanted effects of the near-field measurement equipment on the far-field distribution. Two techniques are based on modulation frequency analysis, a technique that was recently introduced in EMC. The remaining two techniques make use of the cross-correlation with the time-dependent high-frequency components in far field. Two of the four techniques require only low-frequency measurements in near field and are particularly suitable for high power equipment. The proposed techniques are validated by measurements.

Automated summary

This article proposes four techniques for the fast determination of broadband electromagnetic noise sources in complex equipment, avoiding unwanted effects of the near-field measurement equipment on the far-field distribution.