Experimentally Verified Mn–Zn Ferrites' Intrinsic Complex Permittivity and Permeability Tracing Technique Using Two Ferrite Capacitors

Abstract

After setting up a mathematical model for rectangular-shaped Mn-Zn ferrite capacitors, this paper investigates dimensional effects on the intrinsic complex permittivity and the measured apparent complex permittivity of Mn-Zn ferrite blocks. The simple block structure of the samples guarantees their easy and precise preparation. Above a few hundred kilohertz, dimensional effects make the measured apparent complex permittivity deviate from its intrinsic value. This paper uses a Newton-Raphson based method to trace the intrinsic complex permittivity and permeability from the measured impedances of two rectangular-shaped Mn-Zn ferrite capacitors in the frequency range from a few hundred kilohertz to 40 MHz. From the traced intrinsic complex permittivity and permeability, the apparent complex permittivity of a third sample with different dimensions is then calculated theoretically. The papers also presents results of experiments carried out to measure the apparent complex permittivity of the third sample; agreement between the measured and the calculated values is very good. This justifies the validity of the method presented in this paper, when used to determine the dimension-independent intrinsic complex permittivity and permeability of Mn-Zn ferrites