A Rationale for Statistical Correlation of Conducted and Radiated Susceptibility Testing in Aerospace EMC

A conducted susceptibility (CS) test based on bulk current injection (BCI) is designed to ensure correlation of outcomes with typical radiated susceptibility (RS) test procedures foreseen in aerospace/defense standards. It is first shown that deterministic equivalence of RS and CS is awkward due to the lack of knowledge (under common testing conditions) of the common-mode impedance of the equipment under test and the auxiliary equipment. Subsequently, such unknown and uncontrolled setup parameters are treated as random variables, and a statistical rationale is developed to correlate the outcome of CS and RS tests. In particular, the proposed BCI test levels (probe calibration current versus frequency) are related to cumulative distribution functions which quantify the probability of overtesting (i.e., the excess of injected interference) with respect to RS.