An improved open-ended waveguide measurement technique on parameters /spl epsiv//sub /spl gamma// and /spl mu//sub /spl gamma// of high-loss materials

An improved technique of using rectangular waveguide aperture for simultaneous measurement of the electromagnetic parameters /spl epsiv//sub /spl gamma// and /spl mu//sub /spl gamma// of materials is developed in this paper. Both multilayer and single-layer medium sheet samples can be tested. Samples are sandwiched between a flange of an open-ended waveguide and a shorting plate. The parameters are obtained by using an optimization technique by fitting the theoretical values of the reflection coefficients /spl Gamma/(/spl epsiv//sub /spl gamma//,/spl mu//sub /spl gamma//) to the measured values with /spl epsiv//sub /spl gamma//,/spl mu//sub /spl gamma// as the argument. The related details, test theories, waveguide design, sample preparation, and error analysis are also discussed in this paper. The experimental results are validated by the measurements performed using the reflection-transmission method using an automatic network analyzer and the published data from manufactures. By virtue of its open-ended waveguide configuration, this technique is well suited for sheet or coating materials, and it might be applied for industrial on-the-worksite testing or biomedical analysis.