Improvements to the extraction of an AlGaN/GaN HEMT small-signal model

The accurate extraction of AlGaN/GaN HEMT small-signal models,which is an important step in largesignal modeling,can exactly reflect the microwave performance of the physical structure of the device.A new method of extracting the parasitic elements is presented,and an open dummy structure is introduced to obtain the parasitic capacitances.With a Schottky resistor in the gate,a new method is developed to extract R g.In order to characterize the changes of the depletion region under various drain voltages,the drain delay factor is involved in the output conductance of the device.Compared to the traditional method,the fitting of S 11 and S 22 is improved,and f T and f max can be better predicted.The validity of the proposed method is verified with excellent correlation between the measured and simulated S-parameters in the range of 0.1 to 26.1 GHz.