A miniaturized spectroscopy system for complex permittivity detection of organic mixtures in the 0.65–2 GHz frequency range

In this paper, a 0.65-2 GHz miniaturized wideband dielectric spectroscopy system for complex permittivity detection and binary mixture characterization is proposed. The sensing operation is based on using I-Q mixers to measure the change in the magnitude and phase of a microwave signal passing through a capacitive divider when exposed to the material under test (MUT). Unique sensor calibration and detection algorithms are applied for the complex permittivity detection of binary mixtures with a relative error less than 2.5%.