Comparison of Techniques for Measuring High-Temperature Microwave Complex Permittivity: Measurements on an Alumina/Zircona System

The application of microwave energy to the processing of ceramic materials is a promising technology of wide interest, although it still holds some technical challenges. Complex permittivities of many ceramic materials often exhibit significant temperature dependence and influence the volumetric heating behavior of these materials when exposed to microwave radiation. Two techniques have been developed to obtain permittivity measurements up to about 1200°C. These systems have been fully automated, providing results in real time. This paper presents an overview of the measurement systems and measurements on an alumina/zirconia system, showing agreement between the results obtained by both techniques.