BROAD-BAND MEASUREMENT OF ALL COMPLEX PERMEABILITY TENSOR COMPONENTS AND COMPLEX PERMITTIVITY OF FERRITES USING A RECTANGULAR WAVE-GUIDE

We have worked out a broad-band characterization method for magnetized ferrimagnetic materials. The technique is based on the reflection/tra nsmission measurement of the S-parameters of a rectangular waveguide p artly loaded with a ferrite that is to be characterized. The device is set in between the poles of an electromagnet to magnetize the sample. The fundamental principle of the measurement consists in using the an isotropy of the material to lead to the non-reciprocity of the cell (S (11)not equal S-22 and S(21)not equal S-12) in order to have the same number oi information that for the, characteristics we want to determi ne (complex permittivity and all complex permeability tensor component s). In this paper, we will compare in the X-band (8 - 12.4 Ghz) the th eoretical S-parameters of the cell with those measured by the network analyzer for different ferrites of well-known properties in order to v alidate the electromagnetic analysis of the cell. We will underscore t he importance of the losses which are entirely responsible for the non -reciprocity of the S-parameters modulus. To conclude we will suggest a strategy to resolve the inverse problem with an optimization method.