The re-emission spectrum of digital hardware subjected to EMI

I D Flintoft, A C Marvin, M P Robinson, K Fischer, A J Rowell

Research output: Contribution to journalArticlepeer-review


The emission spectrum of digital hardware under the influence of external electromagnetic interference is shown to contain information about the interaction of the incident energy with the digital circuits in the system. The generation mechanism of the re-emission spectrum is reviewed, describing how nonlinear effects may be a precursor to the failure of the equipment under test. Measurements on a simple circuit are used to demonstrate how the characteristics of the re-emission spectrum may be correlated with changes to the digital waveform within the circuit. The technique is also applied to a piece of complex digital hardware where Similar, though more subtle, effects can be measured. It is shown that the re-emission spectrum can be used to detect the interaction of the interference with the digital devices at a level well below that which is able to cause static failures in the circuits. The utility of the technique as a diagnostic tool for immunity testing of digital hardware, by identifying which subsystems are being affected by external interference, is also demonstrated.

Original languageEnglish
Pages (from-to)576-585
Number of pages10
JournalIEEE Transactions on Electromagnetic Compatibility
Issue number4
Publication statusPublished - Nov 2003

Bibliographical note

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  • digital circuits
  • immunity
  • jitter
  • radio frequency interference
  • re-emission spectrum
  • timing delay

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