Microwave thickness measurement of dielectric materials

This paper describes a mechanism which is sensitive to changes in electrical thickness of dielectric materials in the microwave region. The first part of the paper indicates qualitatively how the phase change produced by a radome affects its performance. The relevant properties of a waveguide hybrid-T junction are then briefly described with its application to the sensing head. The sensing head is then described and its performance discussed. A method of controlling electrical thickness using this device, as well as observing it, is finally mentioned.