Field and Circuit Models for the Wound Foil Inductor

The Wound Foil Inductor is an important example of inductive components with appreciable internal capacitance. It is examined from three viewpoints – electromagnetic field theory, distributed‐parameter (or transmission‐line), and lumped equivalent circuit. The analyses are compared, particularly in terms of phase gradients within a component, and the relationship between a two‐dimensional field analysis and the now established lumped model is derived.