An Improved NRW Method for Thin Material Characterization Using Dielectric Filled Waveguide and Numerical Compensation

Abstract

In this article, permittivity measurements based on the Nicholson-Ross-Weir (NRW) technique are reviewed, and an improved method is proposed based on dielectric-filled waveguides and numerical compensation for the electromagnetic performance measurement of the flexible materials or extremely thin materials. The dielectric-filled waveguide used in this work fixes the sample under test without any deformation during the measurement. To improve the measurement accuracy, a modified algorithm is proposed for the inversion of dielectric material and the compensation of measured results. The proposed method is verified by measuring several commercially available materials in the X-band with high accuracy and then used for the characterization of two paper-based composite electromagnetic parameters. © 1963-2012 IEEE.