Abstract: Accurate modeling of the microwave characteristics of III-V compound heterojunction bipolar transistors(HBT's) is extremely useful for microwave power applications of the device.A new large-signal for III-V HBT devices,which is valid for DC,small- and large-signal AC operation, is developed.The model may be used for self-heating effects which are very important for HBT’s.Through the use of several novel features,the proposed approach is differentiated from the UCSD HBT or VBIC BJT representations.Simulation results are verified with comparisons to DC,S-parameters, and large-signal measurements.

Key words: III-V, microwave HBTs, large- and small-signal,  modeling