The GaN HEMT is a potential candidate for RF applications due to the high frequency and large power handling capability.To ensure the quality of the communication signal,linearity is a key parameter during the system ...The GaN HEMT is a potential candidate for RF applications due to the high frequency and large power handling capability.To ensure the quality of the communication signal,linearity is a key parameter during the system design.However,the GaN HEMT usually suffers from the nonlinearity problems induced by the nonlinear parasitic capacitance,transconductance,channel transconductance etc.Among them,the transconductance reduction is the main contributor for the nonlinearity and is mostly attributed to the scattering effect,the increasing resistance of access region,the self-heating effect and the trapping effects.Based on the mechanisms,device-level improvement methods of transconductance including the trapping suppression,the nanowire channel,the graded channel,the double channel,the transconductance compensation and the new material structures have been proposed recently.The features of each method are reviewed and compared to provide an overview perspective on the linearity of the GaN HEMT at the device level.展开更多
基金supported by the Shenzhen Science and Technology Program on Key Basic Research Project undergrant JCYJ20210324120409025the National Natural Science Foundation of China under grant 61904135。
文摘The GaN HEMT is a potential candidate for RF applications due to the high frequency and large power handling capability.To ensure the quality of the communication signal,linearity is a key parameter during the system design.However,the GaN HEMT usually suffers from the nonlinearity problems induced by the nonlinear parasitic capacitance,transconductance,channel transconductance etc.Among them,the transconductance reduction is the main contributor for the nonlinearity and is mostly attributed to the scattering effect,the increasing resistance of access region,the self-heating effect and the trapping effects.Based on the mechanisms,device-level improvement methods of transconductance including the trapping suppression,the nanowire channel,the graded channel,the double channel,the transconductance compensation and the new material structures have been proposed recently.The features of each method are reviewed and compared to provide an overview perspective on the linearity of the GaN HEMT at the device level.
