GaAs MESFET linear amplifiers

RESULTS OBTAINED on microwave linear amplifiers using GaAs Schottky MESFETs will be discussed in this paper. Under common source class A operating conditions, 3-cell MESFETs have delivered output powers as high as 670 mW at 1-dB gain compression at 4 GHz with 35% power added efficiency as follows: [q = (Pout-Pin) /Pdc]. With a 2-cell MESFET, 295 mW was obtained at a -20-dB third-order intermodulation level at 4 GHz under two-carrier operation with 22% efficiency. At 9 GHz, a linear gain of 5.2 dB, an output powero f 300 mW a t 1-dB gain compression and 21% power addeedf ficiency has been achieved. Results on power output, efficiency, third-order intermodulation and AM/PM conversion at G and H bands will be presented.