A 1-D inversion method for permittivity calculations using a non-invasive TDR

Abstract

The non-invasive time domain reflectometry (TDR) technique uses the method of moments to determine the polarized electric field induced by dielectric cells under the action of an impressed field. The contribution from this field to the total field between the transmission lines enables an estimate to be made of the cell’s dielectric permittivity. The geometry currently used for this method of moments integration can be simplified considerably by eliminating redundant cells, either by invoking symmetry or changes in the way the field between the transmission lines is calculated. Here we provide details of the simplification method together with the reduction in complexity that can be achieved.