Extraction and verification of the small-signal model for InP DHBTs in the 0.2–325 GHz frequency range

Abstract

This study presents the extraction and verification of a small-signal model suitable for characterizing THz InP double heterojunction bipolar transistors (DHBTs). The π-type topology is adopted in the intrinsic model. Capacitances C_cx and C_ce are used to characterize the capacitive parasitics caused by the routing line connecting the collector terminal, base terminal and emitter terminal, respectively. The inductive parasitics introduced by the routing line are also considered. The initial values of the model parameters are extracted using a direct extraction method. The model and extraction method for the model parameters are verified by adopting an InP DHBT with 1 emitter finger and an emitter size of 0.5 µm × 5 µm. The simulation results correspond with the measured results in the frequency range from 200 MHz to 325 GHz.