Free-wave measurement of permeability and permittivity of ferrites at millimetre-wave frequencies

Determination of the Gyrotropic Characteristics of Hexaferrite Ceramics From 75 to 600 GHz

“…We have demonstrated in Section III that the magneto-optical constants of a hexaferrite ceramic can be determined over a wide range of submillimter-wave frequencies, from 75 to 600 GHz, using a multi-band vector-network-analyser and a wideband quasi-optical transmissometer. Free-space, or quasioptical, transmissometers have previously been used for measuring the magneto-optical constants of ferrite materials over limited ranges of millimeter-wave frequencies [3,16]. Our measurements cover a much wider, continuous, range of frequency, however, well into the sub-millimeter-wave range, and the methods we use for determining the magneto-optical constants of a material from the measured transmittances of a plate-sample differ from those employed in the measurements made at the lower millimeter-wave frequencies.…”

In Situ Measurements of the Complex Permittivity of Materials Using Reflection Ellipsometry in the Microwave Band: Experiments (Part II)

“…1) The parameter is related to the ratio , according to (14) We remark that is also related to the ellipticity (see Fig. 6) according to (15) 2) The parameters and can be deduced from the angles and according to the two fundamental relations of ellipsometry (16) (17) 3) Thus, the ratio can be determined and, in turn, the value of the relative complex permittivity as implicitly expressed by (2).…”