Systematic direct parameter extraction with substrate network of SiGe HBT

A systematic approach to directly extract the equivalent circuit of the heterojunction bipolar transistor (HBT) including the substrate network is developed. All parameters are extracted from the measured S-parameters. The substrate network is accurately extracted by measuring the collector port Equivalent circuit without substrate effects can be extracted by systematically analyzing and solving the two-port network equations. This technique is validated with fabricated devices in Silicon Germanium (SiGe) technology from 50MHz to 26.05GHz. The extracted results are in excellent agreement with the measured results.