An improved open-ended waveguide measurement technique on parameters epsilon(r) and mu(r) of high-loss materials

An improved technique of using rectangular waveguide aperture for simultane ous measurement of the electromagnetic parameters epsilon(r), mu(r) of mate rials is developed in this paper, Both multilayer and single-layer medium s heet samples can be tested, Samples are sandwiched between a flange of an o pen-ended waveguide and a shorting plate, The parameters are obtain by usin g an optimization technique by fitting the theoretical values of the reflec tion coefficients Gamma(epsilon(r), mu(r)) to the measured values with epsi lon(r), mu(r) as the argument. The related details, such as 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 netwo rk 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 t esting or biomedical analysis.