TM010 mode cylindrical cavity for complex permittivity measurement of liquid using field analysis technique

A 3 GHz TM₀₁₀ mode cylindrical cavity resonator was designed for measuring complex permittivity of liquid material. To improve the measurement accuracy of cavity perturbation method which occurs from variable size of the samples, the field analysis of TM_0n0 cylindrical cavities with two concentric layers of real dielectric at the axis is used. The field analysis method was proposed for calculation of the complex permittivity for liquid material by using the resonant technique. The complex permittivities of distilled water, methanol and ethanol samples were measured. Measured complex permittivity results were compared with the ones acquired by the conventional perturbation method.