A new time-domain approach for determining the complex permittivity using stripline geometry

A time-domain approach for determining the complex permittivity of materials using stripline geometry is presented. The technique uses time-domain reflectometry (TDR) measurements and computer simulation to determine an optimum lossy transmission-line model characterizing the stripline under test. The line model is then used for determining the complex permittivity of the dielectric material. The validity of the technique is demonstrated by using a stripline constructed from Rogers RT/Duroid composite laminate and one constructed from thick-film paste. Accurate estimates for both the Duroid´s and the thick film paste´s dielectric constant were obtained. The technique is incapable of determining the loss tangent if the mismatch between the step generator and the stripline under test is very high and the loss tangent is fairly small