Asymmetrically Split-Cylinder Resonator With Air Gap for Measuring the Complex Permittivity of Film on a Substrate

In this letter, a simple but very effective theoretical analysis is presented for the first time to model an asymmetric split-cylinder resonator (SCR) formed by the loading of multilayer samples. The fringing field effects at the flange can be effectively corrected by equating the multilayer structure to a single one, thus allowing the permittivity of the thin film on a substrate in the asymmetric SCR to be accurately extracted using a simple model of a multilayer dielectric-filled closed cavity. The validity of the proposed method has been investigated both numerically and experimentally at 10–20 GHz.