Mixed mode circuit and device simulation of RF harmonic distortion for high-speed SiGe HBTs

Mixed mode circuit and device simulation has been used to investigated the linearity i.e. harmonic distortion for high-speed low voltage SiGe HBTs. Different Ge-profiles for reduced harmonic distortion have been discussed and compared to a conventional high-speed graded Ge-profile. Other RF figure-of-merits, such as maximum cut-off frequency and minimum noise figure have also been discussed. The influence of the Ge-profile on harmonic distortion was compared to the influence of different epitaxial collector doping profiles.