Time-Domain Mathematical Model of Impulsive Em Noises Emitted from Discharges

Abstract

Impulsive electromagnetic (EM) noises emitted from discharges have been measured and characterized in ultra-wideband VHF channel. Statistical characteristics of EM pulses emitted from single discharge source are investigated as fundamental study. Firstly, the reproducibility of impulsive EM noises is confirmed by calculating their auto-correlations. The frequency spectrums of such pulses are found to be unique for each source. Next, statistical analysis is performed on the amplitude and inter-arrival time of received EM pulses. It is found that the probability distributions of amplitude and inter-arrival time of EM pulses follow normal and exponential distributions, respectively. Taking into account these ultra-wideband characteristics of impulsive EM noises from discharges, a mathematical model of EM pulses emitted from discharges is developed in the time domain. This is represented as a simple analytic formula with three parameters, which are derived from measurements. This model has been validated via measurement where multiple discharge sources exist.