Investigation of Magnetic Permeability of Toroidal Cores

This paper describes the procedure for extracting complex permeability for inductive toroidal cores using short coaxial sample holders in the frequency range between 100 Hz and 110 MHz. Extracting complex permeability from measured input impedance is performed based on the inductive behavior of the coaxial holder. Three numerical techniques based on non-uniform transmission line theory, frequency domain finite difference method, and 3D Method of Moments (MoM) are used to verify above methodology. The obtained results are discussed in detail.