NONLINEAR EFFECTS IN AlGaN/GaN HFET's UNDER LARGE-SIGNAL RF CONDITIONS

摘要

AlGaN/GaN HFET's show promise for providing microwave output power on the order of 10-12 W/mm of gate periphery, In addition, due to the combination of high electron mobility, on the order of μ_n～1200-1500 cm~2/V-sec, and high electron saturation velocity, on the order of v_s=2x10~7 cm/sec, these devices should be capable of operation in excess of Ka band, and potentially to W-band. However, a variety of thermal limitations and physical effects associated with nonlinear charge phenomena related to large-signal RF operation of the device currently limit RF performance. These effects relate to the device structure and can be controlled by proper device design. These effects are discussed.