Uncertainties in coplanar waveguide and microstrip line standards for on-wafer Thru-Reflect-Line calibrations

In this paper the effect of uncertainties in the cross-sectional parameters of CPWs and MSLs (e.g. line geometry, substrate material) on the propagation constants is investigated, and fundamental differences between CPW and MSL are illustrated. Since both planar waveguides can be characterized by on-wafer S-parameter measurements, the propagation of uncertainties when using either CPWs or MSLs as calibration standards for the well-known Thru-Reflect-Line calibration procedure is also investigated.