Attenuation of Common-Mode Currents: Skin Effect and Proximity Effect Optimized Absorptive Low-Pass Filter Layer

The attenuation of common-mode (CM) currents, insofar as their generation itself cannot be avoided, is one of the most fundamental tasks in Electromagnetic Compatibility (EMC). Particularly, CM currents can lead to considerable radiated and conducted emissions. Here, the use of magnetic cores has proven to be effective. However, established EMC measures usually have disadvantages in terms of costs, space, weight as well as practical implementability. As a potentially superior alternative, a new type of absorptive low-pass CM filter layer is investigated in this work. Extensive 3D full-wave simulations of a simple multi-conductor arrangement are being performed in order to optimize the CM surface resistance based on the skin as well as proximity effect, without unduly affecting the differential mode (DM). The initial results are promising. A patent is currently pending.