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

From measurements of transmission through thin sheets and reflection from them, at oblique incidence, both the real and imaginary components of permittivity and permeability of a material can be determined. Except for the generator, antenna and detector system, the apparatus is suitable for any frequency from 15 to 100 GHz. The accuracy of measurement of the real components is believed to be about ±5% and of the sum of the two loss angles about ±0.05 rad, but at the present stage of development values for the two losses separately are more difficult to find.