Noise performance and bias-dependence of Si/SiGe HBT's at microwave frequencies

The results of an investigation on the bias-dependence of the noise performance of Si/SiGe HBT's over the 5-25 GHz frequency range are reported. The noise parameters /spl Gamma//sub o/ and R/sub n/ have been derived from a model analysis based on measurements of the device scattering parameters and minimum noise figure F/sub o/.. The noise behaviour of the HBT and its bias dependence is compared with that of low-noise HEMT's and advanced polysilicon BJT's previously characterised and modelled in our lab.