Asymmetric coupled CMOS lines-an experimental study

This paper investigates the properties of asymmetric coupled lines built in a 0.25 /spl mu/m CMOS technology over the frequency range of 50 MHz to 26.5 GHz. We show that the frequency-dependent line parameters extracted from calibrated four-port scattering-parameter measurements agree well with numerical predictions. We also demonstrate by measurement and calculation that the two fundamental modes of the coupled-line system share significant cross power. To our knowledge, this is the first complete experimental characterization of asymmetric coupled lines on silicon ever reported.