A monolithic 40-GHz HEMT low-noise amplifier

A description is given of a monolithic, reactively matched 40-GHz low-noise amplifier using a 0.25- mu m high-electron-mobility transistor (HEMT) as the active device. Standard processing techniques were used for most of the fabrication steps. An amplifier using a triangular gate profile achieved approximately 6.5-dB gain and a 5-dB noise figure from 38 to 44 GHz. The gain of the amplifier increased to 8 dB and the noise figure decreased to 4 dB when the gate was replaced by one with a mushroom-like profile. The chip size is 1.1 mm*1.1 mm.<>