Transistor noise in SiGeHBT RF technology

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