MEASUREMENT OF COMPLEX PERMITTIVITY OF LIQUIDS USING OPEN-ENDED COAXIAL-LINE AND METAMATERIAL SUBSTRATE

Abstract

The authors suggest a modified technique, based on using metamaterial substrates with known characteristics, which enables one to employ coaxial probes for determining the complex dielectric permittivity of liquids. As it is proven below, by a certain relations between the electric parameters and the thickness of the medium layer to be tested and that of the substrate, there is a resonance decrease of reflections from the probe end, loaded on such a double-layered structure. Knowing this relation, one can determine the complex dielectric permittivity of the tested medium in a wide variation range, using only the measurements of the probe reflection factor amplitudes in a limited frequency range and matching the optimal layer thickness of the medium under investigation.