Indirect Determination of Solute Complex Permittivity Using a Highly Accurate Time-Domain Analysis

A wideband explicit time-domain model for unknown solute complex permittivity is obtained through a rigorous 3-D time-domain analysis of its chemical solution. The latter is assumed as a dispersive medium with measured complex permittivity. In this analysis, a quarter of a slim dielectric probe plunged into the solution is simulated with a high degree of accuracy. To reduce the computational volume, two optimized perfectly matched layers (PMLs) with very thin depth (three cells) are assumed for teflon and water. The performance of these layers is optimized up to 50 GHz. With the help of the optimized PMLs, a genetic algorithm is implemented based on the 3-D finite-difference time-domain analysis to find the best parameters of the solute permittivity model. The complex permittivity of D-glucose is characterized in terms of the one term Debye model after analyzing its solution at 33% of concentration. Obtained results agree well with other measurements of some solutions with different concentrations.