High-speed low-loss micromachined coplanar transmission lines deposited on
a polyimide film were fabricated in a GaAs technology. On-wafer measurement
s of scattering parameters rep to 110 GHz show an effective permittivity ns
low ns 1.08. Special attention was also paid to the tapering section betwe
en the probing and substrateless regions, taking advantage of the etching p
rofile. (C) 1999 John Wiley & Sons, Inc.