Small-signal and noise modeling of submicrometer self aligned bipolar transistor

This paper presents an approach to get a full characterization of microwave bipolar transistors starting from S-parameters measurement only. The analytical form of the Y-matrix representation is derived starting from the /spl pi/-hybrid model (Giacoletto, 1954) and it is used to directly and accurately extract all the parameters of the model. In the second part of the paper the noise sources are added to the equivalent model, and the analytical expression of noise figure is obtained. This expression is used to obtain a full set of noise parameters to characterize the behaviour of the bipolar microwave transistors.