GaN microwave electronics

The progress of AlGaN/GaN based HEMTs is reviewed. The mobility achieved in these modulation doped structures is over 1500 cm/sup 2/ V/sup -1/ s/sup -1/ at 300 K with sheet densities of over 1/spl times/1013 cm/sup -2/. Ft of over 50 GHz and fmax of over 90 GHz has been demonstrated. Power density of over 2.6 W/mm at 10 GHz has been achieved.