Permittivity Measurements in a Resonator Terminated by an Infinite Sample

A method of measuring the permittivity of dielectric materials using a resonator terminated by an infinite sample is described. The method is based on measurements of the changes of the resonant frequency and the Q factor produced by the test sample. The method is particularly suitable for lossy materials with a high dielectric constant, namely, biological substances and tissues. Analytical and graphical solutions, which lead to material permittivity from experimental data, and a discussion of the measurement uncertainty are presented. The experimental results obtained for water are given.