Simplified Approach for Broadband RF Testing of Low Loss Magneto-Dielectric Samples

In this paper, an attractive measurement technique is proposed to retrieve the broadband permittivity and permeability of the magneto-dielectric materials. The proposed technique is quite novel which mitigates the major problems associated with the conventional broadband RF material characterization techniques such as numerical instability and phase uncertainty when the length of the sample exceeds the integer multiple of half-wavelength. The approach adopted in this paper is quite unique as it alleviates the error normally caused by the sensitive phase measurement, since it only employs the relative amplitude of the scattering parameters, thus minimizing the measurement uncertainty. The proposed methodology here is based on the development of a unified scheme for the retrieval of dielectric and magnetic properties of magneto-dielectric samples, which is first tested for a number of reference samples using the numerically generated scattering coefficient data. Finally, the proposed technique is experimentally validated by measuring a number of standard samples over a broad microwave frequency range with the help of the coaxial line and the network analyzer. The dielectric and magnetic properties of samples retrieved using the proposed approach is always found to be in good agreement with their actual values available in the literature.