The GaAs dual-gate FET with low noise and wide dynamic range

The benefits inherent in the tetrode structure and the potential of GaAs as the material are combined to realize a dual-gate FET with a low noise figure and a wide dynamic range at microwave frequencies. Following the newly constructed design theory of GaAs dual-gate FET, an improved device structure is derived and FET's are fabricated using a Schottky barrier for the gate. The improved device exhibited a noise figure as low as 3dB and a power gain of 12dB at 4GHz. The stability factor and maximum stable gain are much larger than the single gate unit. By varying the 2nd gate bias, the power gain was controllable over a wide range of 30dB at 4GHz without significantly affecting the input impedance.