Measurement of dielectric properties for thick ceramic film on an substrate at microwave frequencies by applying the mode-matchig method

In this study, the mode-matching technique (eigenmode expansion) was applied to formulate an analytical model for a split cylindrical cavity resonator with a thick ceramic film layer sandwiched between alumina substrates. Next, resonant frequencies with the TE
₀₁₁
mode were computed with an eigenvalue problem approach using the model formula. The Q value of the resonator was also calculated by applying the perturbation method to the analytical model. The validity of the proposed analytical technique was confirmed using the procedure described below by applying this method to the estimation of complex permittivity for thick film with an inverse problem approach.