Abstract

This paper describes a novel extraction procedure for the intrinsic small-signal model parameters of state-of-the-art 200 GHz SiGe HBTs. Analytical expressions, augmented by a least-square error minimization based optimization, are used to achieve, for the first time, a broadband, small-signal SiGe HBT model that is accurate up to 80 GHz. The intrinsic components for a T-equivalent circuit are determined from open-collector, reverse-bias and forward-bias measurements using proper de-embedding schemes. A bias-independent capacitance i s added in parallel with the intrinsic bias-independent base resistance to model the raised extrinsic base device structure used to achieve the very high fT and fmax found in these advanced SiGe HBTs. The intrinsic components for the physical model are extracted directly from the analytical expressions. The model parameters, extracted from measurements up to 40 GHz, give an accurate representation of the small-signal SiGe HBT characteristics up to 80 GHz. Index Terms — Broadband, small-signal model, SiGe HBTs, parameter extraction, physical model.