Nonlinear modeling of SiGe HBTs up to 50 GHz

A new large-signal model for SiGe heterostructure bipolar transistors (HBTs) is presented that includes nonideal leakage currents, Kirk-effect, and thermal behavior. The parameters are extracted from S-parameter measurements using a special procedure which is insensitive to tolerances in measurement data. The model yields excellent accuracy for dc and S parameters up to 50 GHz. It proved its usefulness in MMIC oscillator design at 26 and 38 GHz.