Modeling of Intrinsic Base Majority Carrier Thermal Noise for SiGe HBTs Including Fringe BE Junction Effect

This paper investigates the impact of fringe BE junction on base majority carrier RF noise in SiGe HBTs. Due to fringe effect, the base hole noise should be modeled by correlated noise voltage source and noise current source in hybrid representation. The noise voltage source can be modeled by a weakly bias dependent noise resistance that is different from the intrinsic base resistance. The correlation between the two noise sources is important for biases around peak f_T