An inverted microstrip resonator for complex permittivity measurement of medium loss liquids using 3D-FDTD simulation

Abstract

A novel microstrip resonator is designed to measure complex permittivities of liquids with medium loss. This resonator has two layers, the first one is the liquid under test and the second one is the base that the patch is printed on it. The base layer is inverted on the sample layer and S-parameter is measured from 0.1 GHz to 1 GHz. The complex permittivities of binary liquid mixtures of methanol and ethanol are reconstructed from the resonant frequency and the quality factor. The experimental results agree with reference values. The maximum errors are 11.34% and 22.12% for the real and imaginary part of the permittivity, respectively.