Identification of rational function in s-domain describing a magnetic material frequency characteristics

High frequency magnetic cores are being used in different applications, from low-power electronic devices, up to high power components. For different material types it is required to identify material-specific equivalent circuit in order to simulate its behaviour in wide frequency range. This paper presents a method for obtaining such an equivalent circuit with the use of a rational function in s-domain such as it represents the material frequency characteristics. For the method presentation the measured data obtained for a real magnetic core was used.