2-D analytical winding losses model of micro-inductor

Since the magnetic field distribution in winding window of thin film micro-inductor with closed magnetic core has obvious 2-D characteristics, the accuracy of 1-D analytical model for its winding AC losses is poor. The magnetic field of the micro-inductor is analyzed deeply to show that its distribution along the winding edge does not change with frequency.

According to the analysis result, the magnetic field strength around the winding edge is calculated with the Ampere’s law. And the 2-D magnetic field is decomposed into an x component and y component in rectangular coordinates. Then based on the superposition and uniqueness law of magnetic field, a 2-D analytical winding losses model of thin film micro-inductor is proposed.

Finally, the finite element analysis (FEA) simulation verified the loss model to have high accuracy under wide exciting current frequency and the loss model can be used easily.