Compact 2-RC Model for Lateral NQS Effects in SiGe HBTs

A physics-based model is proposed to accurately capture the lateral non-quasi-static (LNQS) effects in SiGe HBTs. The model uses new methodology to implement the internal base impedance of the device using two-RC circuits. Equations of all base impedance related components associated with the two-RC network are derived. The proposed model is implemented in Verilog-A. The small-signal AC and the large-signal transient simulations show that the two-RC model yields significantly more accurate results when compared with those of the state-of-the-art model and the π-model.