Wave Analysis of Multilayer Absorptive Low-Pass Interconnects

The attenuation of EMI transmission line filters can be improved at high frequencies by employing eddy current absorption. This is achieved by introducing a material having a low conductivity and/or high permeability in specific regions of the conduction paths. In this paper the ID propagation of a transverse electromagnetic (TEM) plane wave into conductive layers is modeled analytically and used to derive expressions for the field and current distributions in the metal. These results are the basis for computing the frequency dependent ohmic losses of the multi-layered conductive paths in the transmission line filter structures. They form part of a comprehensive analytical filter model, which is suitable for synthesis of integrated RF transmission line EMI filters.