In this paper, a new 3-D electromagnetic (EM) simulation approach for heterojunction bipolar transistor (HBT) parameter extraction in terahertz band is presented. We introduce an inter-electrode impedance equivalent-circuit model with the concept of dispersive parameters and a more rigorous 3-D EM simulation parameter extraction method to avoid serious discrepancies between the simulated EM field distribution and the real EM field distribution of the device. Terahertz parasitic effects, including the EM field discretization and multi-finger device field sharing, are observed. Compared with the previous 3-D EM simulation-assisted model, the new model in this paper demonstrates better results for multi-finger indium phosphide HBTs.
