This paper shows an approach for the broad-band modeling of passive power-supply filter structures, which may be applied to the virtual filter design. The most important advantage of this technique is the possibility of considering the parasitic and functional behavior of a power-supply filter in the same simulation. The approach provides a 3-D model of the filter structure based on a differential field solver. Moreover, the passive components are approximated by combined behavioral-physical 3-D models, which allow the simulation of this structure and the physical volumetric modeling of the current distribution in the components. Thus, the functional behavior of the filter is modeled taking into account all the high-frequency effects (equivalent serial inductance, equivalent serial resistance, parasitic capacitances, punch-grid issues, couplings between components, couplings between interconnections, losses in the plastic environment, etc.). This paper provides a validation of the approach by measurements of a simplified hardware sample and of an industrial filter sample as well.Index Terms-Full-wave modeling, modeling passive components, power-supply filters, virtual design of power-supply filters.