Systematic determination of the propagation characteristics of coplanar lines on semiconductor substrate

A method allowing the systematic determination of the propagation characteristics of micron-size waveguides and overcoming the influence of feeding access discontinuities is presented. The complex propagation constant and characteristic impedance of a slow-wave Schottky contact coplanar line are determined in the 1 to 26 GHz frequency range under different DC bias conditions. This method is successfully used to characterize the Schottky contact coplanar line of micron size under drastic conditions, that is, high value of slow-wave factor, significant attenuation, dispersive transmission line, and strong mismatches between feeding line and device under test. Comparisons with transmission line model theoretical results show very good agreement, despite the large slow-wave factor, attenuation, and dispersion of the waveguide. The electric schemes of the feeding access discontinuities are also presented