An Investigation of the Characteristics of Coplanar Waveguide and Terminations and Coplanar Waveguide Probes for On-Wafer Measurement Applications

Both CPW and GCPW guiding structures have been discussed. Their modal and dispersive properties have been presented both quantitatively and visually. Examples of canonical discontinuities in CPW were presented and computations and measurements were compared. An entirely new examination of a typical on-wafer CPW probe was carried out. Both qualitative, and just as importantly, qualitatively information was obtained through examination of the electromagnetic fields of this general 3-D structure. Computations can have a great role in the design of structures as complicated as a CPW on-wafer probe or as simple as a CPW termination. Concepts like the possibility of multiple modes, localized energy storage, and many other intuitive ideas are now possible. Well calibrated measurements must still be considered the basis upon which to make final judgements, but are limited in the amount of intuitive information they yield. Used in combination, computations and measurements can be even more powerful tools.