A New Microwave Method for Electrical Characterization of Low-Loss Materials

A microwave method is proposed to effectively determine the complex permittivity of low-loss dielectric materials. The method uses raw scattering parameter measurements of an empty cell and a measurement cell (a waveguide or coaxial-line section) with one sample for its two configurations. There are three advantages of the proposed method. First, it does not necessitate any calibration to carry out the microwave measurements. Second, it eliminates the measurement errors arising from sample thickness and inhomogeneity present in the second sample, which is required by other methods. Third, it uses transmission-only scattering parameters of the sample in the theoretical formulations so that it may decrease the measurement errors happening from the phase uncertainty in reflection scattering parameters. The measurement results of two low-loss dielectric materials confirm the accuracy of the proposed method.