A Distributed Model with a High Scaling Accuracy for GaN HEMTs Up to 100 GHz

This report presents a distributed model with a high scaling accuracy for GaN HEMTs up to 100 GHz. Using the distributed model, RF voltage V
grf_i
(i = 1, 2, …, 8) at each gate terminal of N intrinsic transistor models in the finger was simulated. The simulation revealed that the amplitude and phase differences of V
grf_i
in the finger were larger at 100 GHz than at 30 GHz, and the differences were larger when the gate inductance in the finger increased. The simulation results also showed that the gate inductance of the distributed model was more sensitive to gain than that of the non-distributed model and that gain at 100 GHz decreased with increasing gate inductance in the distributed model. The accuracy of the distributed model was verified, and the distributed model was confirmed to reproduce the measured S-parameters well. The MSG/MAG of the distributed model, considering the effect of gate inductance in the fingers, was in good agreement with the measured MSG/MAG up to 100 GHz over a wide gate width range of 30–100 μm. The distributed model was confirmed to be useful for improving the scaling accuracy of sub-THz GaN HEMTs.