A Classic Nonlinear FET Model for GaN HEMT Devices

This paper shows the effective modeling of GaN HEMT devices using Agilent EEHEMT, a commercially available model in Agilent ADS, Microwave Office, etc. Using a series of pulsed IV, DC, S-parameter and Load-pull measurements, a nonlinear large-signal model is extracted to fit the circuit behavior of the device in a real application. Detailed steps are shown in extracting extrinsic and intrinsic parameters in addition to peculiarities of GaN HEMTs in challenging the conventional FET modeling practices. Simulation capabilities of the model are demonstrated through prediction of experimental output power, PAE and input reflection characteristics of a practical amplifier.