Constitutive parameter extraction for heated materials

The focus is the determination of the electrical constitutive paramaters of materials with general complex epsilon and mu values at elevated temperatures. Measurement fixtures and techniques are evaluated for frequencies between 8 and 12 GHz using a rectangular waveguide with the sample completely filling the fixture. Three different measurement techniques are evaluated to obtain the necessary measured quantities for parameter extraction. The most desirable technique used two reflection measurements from material samples of different thickness backed with a short. Temperatures up to 600 F were investigated.