A 0.6-watt U-band monolithic MESFET power amplifier

A high-performance four-stage monolithic microwave integrated circuit (MMIC) power amplifier chip has been developed using 0.3- mu m gate-length and molecular beam epitaxial (MBE) MESFET technologies. These power MMIC chips have been combined to constitute a 47-GHz power amplifier with an output power of 0.45 W and an associated gain of 16.6 dB. A saturated output power of over 0.58 W was also achieved at 47 GHz. These results represent the highest reported power and gain at U-band from a MMIC amplifier using a 0.3- mu m gate-length MESFET. This amplifier has potential application as a driver for a monolithic doubler to obtain more than 80 mW of transmitted power at 94 GHz for W-band system applications.<>