Transistor noise in SiGe HBT RF technology

This brief presents experimental and modeling results of device noise in SiGe HBT RF technology. By careful bandgap engineering, a simultaneous reduction of RF noise, 1/f noise, and phase noise has been achieved. At a given I/sub B/, transistors with different base bandgap profiles show similar 1/f noise. At a given I/sub C/, however, transistors with a higher /spl beta/ (and hence lower RF noise) show lower 1/f noise. Circuit analysis and simulation shows that the phase noise is reduced as well.