Abstract: Based on the basic transit-time domain operation mode of TEDs,we first calculated the ideal maximum oscillation frequency of GaN-based transferred-electron devices (TEDs),which can be as high as 4.7THz.This value is nearly 8 times as high as that of GaAs-based TEDs,which is about 0.6 THz.Next,we calculated the maximum output power of GaN-based TEDs indicating that GaN-based TEDs are promising for high microwave power applications.We also discussed the two critical conditions in GaN-based design for generating stable Gunn oscillations in transit-time domain mode.Our calculation indicates that the product of electron concentration and the length of active layer should be higher than a critical value of 6.3E12cm-2 ;and the doping lever of the active layer has to be smaller than a critical level of 3.2E17cm-3.This study suggests that GaN-based TEDs have significant advantages for high-frequency and high-power microwave generation,which are perspective for high-power THz signal source applications.

Key words: GaN, transferred-electron device, negative differential resistance effect, maximum oscillation frequency, critical doping concentration