Broadband Method for the Determination of Small Sample´s Electrical and Dielectric Properties at High Temperatures

A model for a measurement circuit consisting of a telescopic coaxial transmission line with the sample placed in the gap of the central conductor has been developed and a measurement method, based on this model, was tested. To determine the sample´s electrical properties, the method requires the measurement of the two-port scattering matrices of the short-circuited line, the line with one calibration sample, and the line with the sample to be measured inserted. The model takes into account the thermal elongation of the measurement line and can be used for measuring electrical properties of materials at high temperatures in the megahertz and gigahertz ranges. This model also reduces the influence of parasitic reflections in the measuring coaxial line on the measurement results and takes into account a complicated distribution of the electromagnetic field in the measuring capacitor without solving a complicated electrodynamics problem.