Power GaAs FETs

This paper reviews progress in the development of GaAs FETs for microwave power applications. At Texas Instruments over 5W cw output power has been achieved from a single device at 9 GHz and over 1W at 16 GHz. (1-3) Fujitsu (4) and Bell Laboratories (5) have obtained 10W at 4 GHz. Power added efficiencies of over 30% were achieved at these power levels. Power FET structures that are being developed at Texas Instruments and other laboratories are described and compared. The most recently reported microwave performance results are given, and the possibilities for achieving higher power levels considered.