Noise bipolar models for SiGe HBT

This work is dedicated to compare the state of art of Y-parameter based bipolar noise models using a SiGe low noise heterojunction bipolar transistors. Minimum noise figure, F/sub min/, comparison is done using measured and simulated Y-parameters and both are compared with F/sub min/ measurements. It is shown that a good agreement is only obtained at low currents. The discrepancies between measured and modeled F/sub min/ are discussed.