A K/Ka-band distributed power amplifier with capacitive drain coupling

A 14- to 37-GHz GaAs MMIC distributed power amplifier is discussed. The amplifier has three FETs of varying periphery, all capacitively coupled to the gate line. The drain of the FET nearest the output is capacitively coupled to the drain line to increase output power. A gain of 4 to 5 dB has been achieved from 14 to 37 GHz. Output power of 20 dBm or greater has been demonstrated at frequencies up to 33 GHz at 1-dB gain compression. A maximum 1-dB gain-compressed output power of 23.5 dBm (220 mW) has been measured at 36 GHz. The circuit is completely monolithic, with all bias and matching circuitry included on the chip.>