Novel evaluation method for complex high permittivity of BaTiO3 families at microwave frequency

A simple but practically accurate measurement technique in microwave region for the extremely high dielectric constant of ferroelectric materials is proposed using the ring shaped specimen placed on the short end metal of coaxial line. The complex permittivity is estimated by inverse fitting the measured S-parameters of test fixture loaded with specimen to the most probable permittivity values of specimen using finite element method (FEM). The new method provides an easy way to evaluate the high complex permittivity exceeding 10000, which is difficult to be measured by the currently used measurement techniques.