Complex Permittivity Measurements of Liquids using a Microwave Dielectric Resonator

Some substances as "liquid crystals" are not available in large quantities. In this paper, we present a measurement method of complex permittivity of liquids in Land C bands. This method is based upon the study of resonance frequency of the magnetic dipole mode TE01¿ oscillating in a dielectric tubular resonator which contains the substance to characterize. Validity of the model is tested with well known liquids. We exhibit optimalization possibilities of the cell in order to measure low losses materials. Absorption characteristics of the p-methoxypheny lazoxy-p¿-butylbenz¿ne (M.P.A.B.B., nematic in the range 16 - 76°C) are then measured to illustrate the reliability of the method.