New pseudomorphic N/sup -//N/sup +/ GaAs/InGaAs/GaAs power HEMT with high breakdown voltages

A pseudomorphic N/sup -//N/sup +/GaAs/InGaAs/GaAs power HEMT (high electron mobility transistor) with high breakdown voltages (VB) of more than 20 V and full channel current of 460 mA/mm is described. This power HEMT allows the simultaneous improvement of output power (P/sub out/), linear gain (G/sub L/), and power-added efficiency (N/sub add/) over GaAs FETs. A record maximum output power of 4.7 W at 14.25 GHz was achieved by a large 10.5-mm-wide HEMT chip with G/sub L/ of 8 dB and N/sub add/ of 25%.<
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