Assessing linearity of injection probes used in BCI test setups for automotive applications

In this work, the possible occurrence of saturation in injection probes for Bulk Current Injection (BCI) is experimentally investigated. To this end, three different probes are considered. These probes are suitable for conducted susceptibility verifications foreseen by automotive Standards. The probe transmission performance is characterized in terms of insertion loss for different power levels delivered to its input port, with the objective to assess probe linearity during the injection test. For the probes under analysis, the results shown in this paper led to exclude the occurrence of saturation even when the probes are used in combination with the most severe injection profiles foreseen by specific BCI Standards. The significance and usefulness of this result is that modeling of injection probes in terms of suitable frequency-responses appears to be feasible, and can therefore be used for effective simulation of test setups and the prediction of BCI test effects.