High gain and high efficiency K-band power HEMT with WSi/Au T-shaped gate

We have developed WSi/Au T-shaped buried gate pseudomorphic HEMT with the good uniformity of recess current by using a selective etching process and with a high off-state break down voltage of over 19 V. A 1.4 W output power has been obtained with a power-added efficiency of 55.6% and an associated gain of 9.2 dB under high voltage operation of Vd=10 V at 18 GHz. This is the highest gain and efficiency achieved by a single FET chip with over a watt output power at this frequency.