On the equivalence between radiation and injection in BCI testing

Bulk current injection (BCI) and field coupling are analytically compared in order to ascertain if current injection tests are adequate for susceptibility assessment of electronic equipment. Transmission line theory is adopted for modelling wiring harnesses, and the equivalence is discussed by comparing the effects that the two kinds of excitation techniques produce at the line ends. General results are obtained, which are not affected by any assumptions on the equipment under test. It is shown that, from the theoretical point of view, injection by means of two current probes allows equivalence with any radiated plane wave excitation. The equivalence is achieved by controlling the clamp voltage in order to match the incident field characteristics