A measurement system for radiated transient electromagnetic interference based on general purpose instruments

Abstract

This paper presents a measurement system intended to be used to assets the radiated electromagnetic interference (EMI) in both time and frequency domains. In order to keep the measurement setup as accessible and practical as possible, the direct measurements are recorded with a general purpose digital oscilloscope and processed with a commonly available personal computer. The measurement system was validated for radiated emissions testing using well-known, controlled transient and continuous signals emulating typical interferences. The results are in satisfactory agreement with those provided by a conventional EMI receiver for different types of detectors. The proposed approach shows that, currently, it is possible to implement a timesaving, accurate and generally inexpensive time domain measurement system for radiated emissions that is capable to overcome the limitations of the superheterodyne EMI receivers regarding the measurement of discontinuous electromagnetic disturbances and also able to provide additional enhanced features to evaluate and troubleshoot EMI problems.