A GaAs Microwave MESFET with Extremely Low Distortion

A ku-band GaAs power FET with extremely low signal distortion was fabricated on a material with graded doping profile, grown by a special vapor phase epitaxy technique. The device has a nearly constant gm over a wide range of the bias. At P/sub o/ = 18 dBm and P/sub sat/ = 24 dBm power levels of a 6 to 18 GHz broad band amplifier, this device demonstrates second harmonic levels as low as 40 dBc and 22 dBc , respectively, which is the lowest ever reported.