Wideband characterization and modeling of coupled inductors under temperature variations

Coupled Inductors are widely used in EMI power filters. The impact of temperature on the frequency behavior of these components is very significant and shouldn't be neglected. In this paper, characterization test-benches and modeling methods of coupled-inductor impedances via measurements are presented for two types of magnetic cores: nanocrystalline alloy and Manganese-Zinc (Mn-Zn) ferrite. The aim of this study is to propose relatively simple models in order to estimate the thermal behavior of these components by simulation, for frequencies ranging from 10 kHz up to 100 MHz and temperatures ranging from -40°C up to 200°C. The new model is simulated and the obtained results are compared to the experimental measurements in the frequency domain. The developed model is then translated to VHDL-AMS language for easy implementation in most electrical simulation softwares.