Simulation and analysis of high-frequency low-profile inductors

The relationship between the power loss, winding and core geometries of the high-frequency low-profile (HFLP) inductor is investigated with the aid of finite element method. The simulation results have shown that a magnetic core with lumped air gaps can cause excessive loss in the windings, and the core loss depends on the air gap size and the high frequency characteristics of the magnetic material. The geometry of the winding is a significant factor to determine the total AC loss. The optimal thickness of the inductor winding is determined by the length and distribution of air gaps. The multi-layer winding arrangement is believed to be the most promising solution to reduce the power loss and leakage field. The finite element analysis also indicates that the total loss in the inductor with square-wave current excitation is over double that with sinusoidal excitation. Practical design rules are given along with the simulations.