The measurement of permittivity of high-loss liquids at microwave frequencies using an unmatched phase changer

Abstract

The behaviour of an adjustable length of coaxial line containing a standing wave is considered theoretically. It is shown that a relationship can be obtained between the change in the line length and the resulting change of phase. This is then followed by a description of how the complex permittivity of a liquid such as water can be measured using the phase changer in conjunction with a phase-amplitude balance method.