Accurate Microwave Resonant Method for Complex Permittivity Measurements of Liquids

Abstract

In this paper, a method available for accurate mea- surements of lossy liquids is presented, tested on standard mate- rials, and compared with the perturbation technique commonly adopted in cavity measurements. The method is based on numer- ical solving a complex characteristic equation. Realization of the method was done using an cylindrical cavity. Results show that measurement errors may be decreased with application of the method presented. The method excludes uncertainties in complex permittivity determination when material has losses and high per- mittivity.