The bulk current absorption technique for evaluation of coupling between radiated fields and wiring harnesses

The wide range of EMC facilities and services at MIRA (Motor Industry Research Association) provide the ideal environment for evaluation and comparison of measurement techniques. Whole vehicle radiated immunity is most often used to assess the performance of vehicles and their subsystems when subjected to electromagnetic interference, whilst bench methods such as bulk current injection (BCI) are popular for development work on the subsystem alone. Work performed at MIRA suggests that the coupling between radiated fields and wiring harnesses is influenced by both the antenna position and the structure of the vehicle. Data obtained using the bulk current absorption (BCA) technique, where a current probe is used to measure the RF currents induced on the harness of the vehicle, is presented to demonstrate these effects and to suggest more suitable levels for the transfer function.<>