A comparison of intermodulation distortion performance of HICUM and VBIC compact models for pnp SiGe HBTs on SOI

Abstract

This paper presents the characterization of intermodulation distortion in pnp SiGe HBTs on SOI. For the first time, measured results of pnp SiGe HBTs are compared against Spectre-based simulations using both HICUM and VBIC compact models, after the systematic selection of the appropriate corner models. It is shown that the HICUM model more accurately captures distortion effects than the VBIC model, across a wide range of collector voltages and currents. HICUM is also superior in modeling large-signal nonlinearities such as gain-compression. These results have clear implications for the best-practice design of distortion-sensitive high-frequency SiGe analog and RF circuits.