Millimeter wave dielectric measurements at elevated temperatures

Interest in the constitutive parameters of materials at elevated temperatures continues to increase as new materials are developed for high-temperature applications. A simple, relatively nondestructive method for testing materials at millimeter wave frequencies is presented here. Measurements have been performed between 30 and 100 GHz at temperatures up to 1500 degrees C in a commercially available furnace. Measurements to date have been performed on dielectric materials with dielectric constants ranging from 1.2 to 10. The measured dielectric constant and loss tangent of a low-loss foam material are shown.<>