High frequency effects in planar magnetics: inclusive of skin effect

Planar magnetic components are playing an increasingly important role in the goal of increasing the power handling capability of power supplies, and in the fabrication of magnetic components using microelectronic techniques. Resistance of these devices varies greatly over their operating frequency range, due to magnetic flux linkage within the wide flat conducting sections. However, it is not possible to calculate resistance with conventional formulas for each different frequency. This paper proposes a new method for evaluation of losses, so that magnetic devices of known resistance and Q-factor can be designed over a wide operating frequency range. Improved designs are possible using this new procedure without the expensive steps of building prototypes and testing.