A wideband two-layer microwave measurement method for the electrical characterization of thin materials.

摘要

A novel measurement method was developed to characterize the electrical properties of specific materials within strict requirements. The main measurement parameters needed include the ability to measure thin, lossy materials over a broad frequency range in a relatively expedient manner. The method developed uses a two-layer structure, consisting of a layer of thin, flexible unknown material supported by a thicker, rigid known material that enables accurate placement inside a waveguide for measurement. A non-linear leastsquares optimization algorithm is used to converge on the complex permittivity and permeability of the material. An uncertainty analysis is performed to investigate optimal thicknesses of both the sample layer and the supporting layer. Simulations in FDTD were constructed to explore the effects of sample layers that are not of exact dimensions. Results from many different materials show the repeatability, and accuracy of the data set convergences, as well as several limitations of the procedure.