Analytic model of structural effects in toroid cores with rectangular cross section

In this paper the high frequency dimensional effects in toroid cores made of soft ferrite are examined. An analytical method is used in which the field distribution is calculated by means of separation of variables. Based on the results, the influence of permittivity and conductivity of the core material on the flux distribution is discussed. The calculated results are compared with measured data to validate the model. Finally a method to reduce the influence of the dimensional effects is shown.