1-D FEM-Based Approach for Extracting Dimension-Independent Material Properties of Mn-Zn Toroidal Ferrite Cores

This article presents a finite element (FE) method (FEM)-based approach for identifying the dimension-independent magnetic and dielectric properties of Mn-Zn toroidal ferrite cores. Two 1-D axisymmetric FE models are used for solving the full-wave electromagnetic field equations in a toroidal ferrite core using either the electric field strength (
$\boldsymbol {E}$
) or the magnetic field strength (
$\boldsymbol {H}$
) as the variable. Impedance measurements are performed for the toroidal cores over a frequency range of 10 kHz–10 MHz. The FE models and the impedance measurements are combined with a non-linear least-squares algorithm for solving the inverse problem for extracting the dimension-independent values of complex permeability and complex permittivity. The extracted permeability is validated against the datasheet of the measured samples.