Modeling and Prevention of Electromagnetic Leakage Scenarios in Automotive EMC Shielding

The aim of this paper is to show the modeling of the possible ways of electromagnetic leakage in a shielding. The research collects scenarios of a wide frequency range, from a few kHz to the GHz domain; this includes the transparent wall, the outgoing surface currents, and the wave propagation through small gaps and apertures. Beside the modeling of the leakage path, a characteristic frequency range is assigned to each one, and the associated protections are also listed. This assignment becomes important when a limit violation appears in a radiated emission test because the measured result by itself does not carry any information about the path of the leakage. However, by discovering these, it is possible to infer the cause of the failure and perform a prevention against it. One of the leakage scenarios is thoroughly examined, the case of the outgoing surface currents originating from capacitive or inductive coupling, and it is demonstrated through FEM simulations, how to protect against this leakage. The tool of the protection is an RF-trap, which can decrease the electromagnetic field outside by reducing the leaking currents.