A fast numerical technique for the determination of electrical properties of materials

This paper presents a numerical technique particularly suited for the determination of the dielectric properties of unknown materials. The technique is based on the Boundary Integral-Resonant Mode Expansion (BI-RME) method combined with a segmentation technique. The circuit under test is subdivided into homogeneously-filled building blocks. Due to the particular pole-expansion representation of the admittance matrix of each building blocks, where the complex dielectric constant appears explicitly, the iterative identification of the unknown electrical characteristics of the material does not require repeated full-wave analyses. A computational example based on a simple yet meaningful canonical shape is reported, to demonstrate the accuracy of the proposed technique. Moreover, the algorithm for the automatic identification of the material characteristics in case of general shapes is discussed.