Dielectric properties of alumina ceramics in the microwave frequency at high temperature

Abstract

The dielectric properties of alumina ceramics have been measured using a free-space time-domain technique from room temperature to 1400°C in the frequency range 8.2 - 12.4 GHz. The effects of thickness and lateral size of specimen were investigated with comparing the measured values to the calculated ones based on the half-wavelength and the Gaussian beam focusing. From these results the optimum specimen dimension for the high temperature dielectric measurement was suggested with experimental verification.