GaN and AlGaN static induction transistors (SITs) are simulated using a two-dimensional self-consistent drift-diffusion simulator incorporating impact-ionization and self-heating effects. The results indicate that GaN SIT devices can have performance comparable to SiC SITs. As compared to GaN SITs, AlGaN SITs will have higher breakdown voltage but smaller maximum current. The power per unit gate width obtainable from GaN and AlGaN SITs are approximately the same, but the maximum power handling capacity of the AlGaN SIT is significantly higher due to bigger optimum load resistance. A comparison of the characteristics of GaN and AlGaN SITs with AlGaN/GaN HEMTs shows that the SIT devices have much lower cut-off frequency and smaller transconductance but can produce higher total output power. © 2006 Elsevier Ltd. All rights reserved.