Asymmetric coupled CMOS lines - An experimental study

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