Abstract

We present theoretical and experimental data in the frequency spectrum and doping concentration that show the variation of the effective index of refraction neff from a "slow wave" mode into the "lossy dielectric" mode for Coplanar-Waveguides (CPW) fabricated on GaAs substrates. We show that this variation can be modeled by an equivalent transmission line circuit model based on a quasi-static approach using two effective physical parameters (i) the thickness of the lossy layer and (ii) the conductivity.