A unified approach to RF and microwave noise parameter modeling in bipolartransistors

A unified approach to RF and microwave noise parameter modeling in bipolar transistors is presented. Circuit level noise parameters including the mini mum noise figure, the optimum generator admittance, and the noise resistanc e are analytically linked to the fundamental noise sources and the gamma -p arameters of the transistor through circuit analysis of the chain noisy two -port representation. Comparisons of circuit level noise parameters from di fferent physical models of noise sources in the transistor were made agains t measurements in UHV/CVD SiGe HBTs. A new model for the collector shot noi se is then proposed which produces better noise parameter agreement with me asured data than the SPICE noise model and the thermodynamic noise model, t he two most recent Y-parameter based noise models.