Mechanism of Conductive Losses in a Sandwich-Structured Planar Inductor

In this paper conductive losses in a sandwich-structured planar inductor are discussed. Analysis by FDM (finite difference method) of the current distributions in a rectangular conductor sandwiched between magnetic material revealed that the current is concentrated near the conductor edges. It is also shown that filling gaps with magnetic material is effective for reducing ac resistances, especially when the width of the conductor is much larger than the skin depth.