High-power microwave 0.25-μm gate doped-channel GaN/AlGaN heterostructure field effect transistor

We report on the high-power performance of the 0.25-mu m gate Doped-Channel GaN/AIGaN Heterostructure Field Effect Transistors (DC-HFET's), At a drain bias voltage of 18 V and drain bias current of 46 mA, these 100-mu m wide devices exhibit high gain at 8.4 GHz with a power density reaching 1.73 W/mm. The de,ices also display high gain at moderate power over a wide range of frequencies, This high gain at high frequency is a result of an optimal doping level in the AIGaN layer that gives rise to a high sheet charge density while maintaining a high-channel electron mobility. These results demonstrate the excellent microwave power capability of the GaN/AIGaN based heterostructure field effect transistors.