This paper presents a method to assess intentional electromagnetic interference (IEMI) in a linear multiport system, due to coupling with a high-power electromagnetic (HPEM) field. First, an approach based on the Lorentz reciprocity theorem is proposed to model field coupling for arbitrary direction of incidence and polarization, which minimizes the number of required full-wave numerical simulations. Afterwards, three constrained-optimization problems are identified to describe the worst-case scenarios related to different radiated-susceptibility effects at the system’s ports. Namely, under the assumption of limited bandwidth and finite energy density, the spectrum and waveform of the HPEM field are found so to maximize the dissipated energy, the peak, and the rectified impulse of the induced voltage waveform. It is shown analytically that in the worst-case energy scenario, the HPEM field shall be a properly tuned narrowband field, whereas in the worst-case voltage peak scenario a wideband field properly matched to the frequency response of the system is needed. Additionally, it is shown that the rectified impulse of the induced voltage can be made arbitrarily large by reducing the impinging field bandwidth. A typical printed-circuit board interconnect for low-voltage differential signaling is used to exemplify and validate the proposed approach. Furthermore, uncertainty-quantification techniques are exploited to cope with lack of knowledge about the incidence and polarization parameters of the HPEM field, as well as to account for uncertain geometrical parameters of the victim system.

This work is concerned with the assessment of radiated susceptibility of a victim system subject to wideband, intentional electromagnetic interference. It is shown that the high-power electromagnetic (HPEM) pulses giving rise to worst-case interference, according to predefined susceptibility criteria, can be readily determined thanks to a reciprocity-based approach. Particularly, for a specified bandwidth and energy density, the worst-case HPEM pulse waveform maximizing the voltage peak induced across an electric port is found by solving an optimization problem. The solution requires a single full-wave simulation of the victim system, treated as an unintentional radiator, to find its input impedance and radiation pattern. A repeated-run analysis involving limited computational burden allows obtaining the statistics of the worst-case HPEM signal for random incidence and polarization. In order to exemplify the proposed theory and results, the case of a hyperband pulse impinging onto a system composed of two units interconnected by a wiring harness is addressed.

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.

Metal-oxide arresters (MOA) are widely used to protect equipment against transient electromagnetic disturbances (TED) like very fast transient overvoltage (VFTO), high-altitude electromagnetic pulse (HEMP), lightning pulse, et al. Researches on the performance of MOA under microsecond level rise-time TED are abundant, such as lightning pulse. However, when MOA is subjected to TED of rise-time at nanosecond level, the voltage/current responses of MOA are not fully studied due to the lack of a standardized and reliable test setup. In this paper, a test setup is proposed for acquiring the response behavior of MOA under nanosecond level pulse. The setup is comprised of a pulse generator, a two-branch transmission line system and a high voltage power divider. The generator can provide stable double exponential pulse with tunable rise-time ranging from 5 ns to 100 ns. The divider ensures an even distribution of voltage/current surge wave along the two-branch line. Through the numerical analysis, both impinging and residual surge waveforms could be retrieved from measurements. The proposed method has been applied to investigate response behavior of MOA subjected to nanosecond level rise-time pulses.

In this letter, we consider the scenario that a linearly polarized electromagnetic plane wave excites a transmission line (TL). By tailoring the reciprocity theorem for modeling the field-coupling problem, we prove that the maximal/minimal coupling scenarios can be determined from the radiation pattern data. Particularly, the incidence and polarization angles of the field that maximize/minimize the coupling efficiency of a matched TL are solved in a closed form. Accordingly, design guidelines have been proposed for the protection of TL from electromagnetic interferences.