Superior low-noise GaAs MESFET's with graded channel grown by MBE

GaAs MESFET's with superior microwave performance were fabricated with uniform and nonuniform doping profiles grown by molecular-beam epitaxy (MBE). At 8 GHz the devices with graded doping exhibited about 1 dB higher gain at the minimum noise figure point compared to flat doping profile devices. The noise figure of 1.38 dB with an associated gain of 8.6 dB at 8 GHz was obtained for the best device with a graded profile.