研究了蓝宝石衬底 Al Ga N/Ga N共栅共源器件的特性。该器件包括栅长 0 .8μm共源器件与栅长 1 μm的共栅器件。研究表明 ,共栅共源器件的第二栅压对的器件饱和电流与跨导有明显的调制作用 ,容易实现功率增益控制。与共源器件相比 ,共栅共源器件在微波特性上 f T 大约 9GHz,比共源器件稍小 ,但是具有较低的反馈 ,显著增加的功率资用增益及较高的端口阻抗 ,与共源器件相比 ,稳定性更好 ,可以避免振荡的产生 ,结合 Ga N的高功率特性 Ga
Fabrication and characteristics of cascade connected AlGaN/GaN HEMTs grown on sapphire substrates are reported.The circuit employs a common source device,which has a gate length of 0.8μm cascode connected to a 1μm common gate device.The second gate bias will not only remarkably affect saturated current and transconductance,but also realize power gain control.Cascode device exhibits a slight lower of f T,a less feedback,a largely greater of maximum available gain and a higher impedance compare to that of common source device.
