Worst-Case Wideband Radiated IEMI for Unshielded and Shielded Cables: A Statistical Analysis of the Main Influencing Parameters

This study deals with intentional electromagnetic interference and presents statistical analysis of common-mode and differential-mode disturbances induced in unshielded or shielded cables by a radiated, wideband, high-power electromagnetic (HPEM) pulse. The quantity of interest is the worst-case (i.e., maximum) peak in the time-domain waveform of the voltage that can be induced in a terminal interface of the harness by an HPEM pulse with specified bandwidth and energy density. Statistics is required to account for the lack of knowledge on the direction of incidence and polarization of the impinging plane-wave field, which are treated as random variables. Consequently, the worst-case induced-voltage peak is characterized by a cumulative distribution function (cdf). The analysis puts into evidence the different properties of the cdf for unshielded and shielded cables, with reference to the influence exerted by the main system parameters, including the cable length, the height above ground, and terminal impedances.