SiGe HBT Large-Signal Table-Based Model With the Avalanche Breakdown Effect Considered

In this paper, a table-based large-signal model for silicon germanium heterojunction bipolar transistors with the introduction of a breakdown network is presented to describe the avalanche breakdown effect of the base-collector junction on direct current and RF characteristics completely. Input oscillation and output inductive behaviors in the breakdown regime are found to be due to impact ionization induced holes and electrons, respectively. The avalanche breakdown effect and early effect modeled by the breakdown network and output resistance, respectively, can be distinguished in the presented model. In addition, a good agreement between the extracted total input and output resistances at RF and dc is obtained. The validity of this presented large-signal table-based model with multibias intrinsic parameters has been verified through the measured output spectrum and waveform.