Using the root-mean-square detector for weighting of disturbances according to its effect on digital communication services

The issue of finding a new electromagnetic interference (EMI) measurement detector with proper weighting properties for the effect of disturbances on digital communication services is of great importance for the development of future emission standards. We investigate the root-mean-square (RMS) detector as a possible candidate for future emission measurements. This investigation is done for type of disturbances typical for information technology (IT) equipment, i.e., a repetitive pulse waveform. We show that the tolerated RMS value of the disturbance level related to a certain bit-error probability is in practice independent of the pulse width of a repetitive pulsed disturbance signal. Furthermore, the variation of this tolerated RMS value with the pulse-repetition frequency of the disturbance can easily be modeled. These properties make it possible to express the maximum allowed disturbance level in terms of the output from the RMS detector. The conclusion is that the RMS detector is a promising candidate for future emission standards where the disturbance effect on digital communication services is considered.