A direct technique for determining complex permittivity of dielectric material in a measurement cavity

In this paper, a direct technique for determining complex permittivity of dielectric material in a cylindrical measurement cavity is presented. The method is based on a recently proposed enhanced spectral domain approach. In this analysis, a electromagnetic model related to a composite cylindrical cavity is derived. Based on this model, the two fundamental problems (the direct and inverse problems) for cavity measurement systems are discussed in detail. A number of numerical examples are given to verify the proposed technique. The effect of structural parameters of the cavity on measurement accuracy is studied