Systematic Experimental and Simulation Studies of Dimensional Resonance in Mn-Zn Ferrite Toroidal Cores

This paper presents accurate simulation of the magnetic properties of manganese-zinc (Mn-Zn) ferrite toroidal cores using the dimensional resonance effect. We prepared as-sintered Mn-Zn ferrite toroidal cores with systematically varied dimensions and precisely measured their complex permeability and loss at frequencies of up to several MHz. We also performed magnetic simulation for core models with real shapes by combining the finite element method with an equivalent circuit model that describes the capacitive behavior at high-resistive grain boundaries in polycrystalline Mn-Zn ferrite. We showed that the systematic variation of permeability according to the core size observed in the experiment was in good agreement with the simulation, from which we confirmed accurate prediction of the dimensional resonance effect. We also revealed that the frequency dependence of core loss in the experiment was well reproduced by the magnetic simulation.