Measurement of High Permittivity Dielectrics at Microwave Frequencies

Abstract

Apparatus is described for measurement of the complex dielectric constant of liquids of high permittivity in the range from 1 to 10 cm wavelength. The method is chosen for sensitivity in the region of high permittivity and requires no moving parts or measurements within the sample. Transmission coefficients of samples contained between mica windows in short sections of wave guide are measured by mixing the wave transmitted through the sample with a wave of fixed amplitude and phase traveling in the opposite direction. The resulting standing wave pattern is detected with a traveling probe. Equations are given relating primary data with dielectric properties of the samples, and solutions are obtained by graphical means.