For energy efficient power conversion, fast switching power semiconductors are used within power electronics. The switching can lead to disturbances of other electrical devices because of interference on the power line and in the air. The common aluminium heat sinks for the cooling of the power semiconductors are electrically conductive and lead to more interference. Using an electrically isolating ceramic heat sink is an approach to reduce the interference from the heat sink.

In this contribution the effects of repetitive pulse excitations on linearly and nonlinearly loaded antennas are studied on the basis of equivalent circuit models. This is important to understand in the context of Electromagnetic Compatibility possible nonlinear effects which often are not included in the analysis. It is found that a surprisingly large capacitive effect can be produced which has no counterpart in the linear case and is accompanied by the storage of unwanted electric energy.