High Frequency Small-Signal Modelling of GaN High Electron Mobility Transistors for RF applications




Liu, Zhen

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In this project, a 16-element Bias-Dependent Small-Signal Model (BD-SSM) equivalent circuit for the Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) is developed. Intrinsic and extrinsic values of the proposed model are extracted from S-parameter data measured at different bias conditions. This model has multiple sets of circuit element values and each set is tuned using Advanced Design System (ADS) for a particular bias condition. Moreover, GaN HEMTs of various sizes are modelled using the proposed BD-SSM equivalent circuit for the evaluation of GaN-based transistors. The modelling results have less than 2% deviation when compared to the measurement values; this is significant since all published results known to us have 5% or higher percentage deviation. Therefore, the proposed BD-SSM equivalent circuit is one of the most accurate GaN HEMT model for amplifier design in today’s Radio Frequency (RF) applications.



small-signal model, gallium nitride, high electron mobility transistor, transistor modelling