Coplanar Waveguide Vs. Microstrip for Millimeter Wave Integrated Circuits

Using a full wave analysis, coplanar waveguide transmission line is compared to microstrip in terms of conductor loss, dispersion and radiation into parasitic modes. It is shown that, on standard .1 mm semiconductor at 60 GHz, the dimensions of coplanar waveguide can be chosen to give better results in terms of conductor loss and dispersion than microstrip. Curves are presented comparing the microstrip open end and the coplanar waveguide short circuit in terms of parasitic mode generation.