Time-domain characterization of bent coplanar waveguides

A comprehensive experimental study of the propagation of picosecond steplike transients on bent coplanar waveguides (CPWs) on GaAs substrates is presented. Bent CPWs with different degrees of bend-smoothing were investigated with the aid of a subpicosecond electrooptic sampling system. The observations indicated that the physical length of the bent CPW had to be taken into account in order to evaluate the signal propagation velocity correctly. Smoothing of the bends significantly improved the HF performance of the lines. The results demonstrate that transients with a bandwidth in excess of 100 GHz suffer only limited signal distortion when they are propagated over substantial distances on bent CPWs.>