The Influence of Ferrite Characteristics on the Inductance of Coils With Rod Cores

In this paper, the influence of material parameters on the inductance of a coil with a rod core is analytically calculated and verified by measurements and simulations. The magnetic field is split up into the field from the air coil alone and in a second part, which takes the influence of the rod core into account. To calculate the influence of the core the field, equations are solved by means of an orthogonal expansion using piecewise defined orthogonal functions with complex eigenvalues. A matrix calculus is introduced in order to obtain a compact mathematical formulation and a relatively simple evaluation on a PC