A Novel Method for the Determination of the Dielectric Properties of Liquids at Microwave Frequencies

At microwave frequencies the precise knowledge of the electromagnetic properties of materials is essential. In this article, methods for the determination of the permittivity of liquids are presented. The methods are based on scattering parameter measurements with the help of a vector network analyzer. For the precise extraction of the material parameters and the elimination of systematic errors of the setup, self-calibration procedures, the LNN (line, network, network) and the LRR (line, reflect, reflect) method, are applied. Both methods have in common that the material parameters are already calculable within the so-called self-calibration procedure, so that a full two-port calibration of the whole setup is not necessary. Furthermore, the methods can be realized effectively in a practical setup having the advantage that a rearrangement of the setup is not needed for the material parameter measurements