Power Combined Amplifiers for Terahertz Varactor Sources

The development of broad-band power amplifier MMICs from 120 GHz and above is enabling a new generation of varactor sources. Power combining is an essential technique to maximize the amount of power available from these devices. Two, four and eight-way combining of four different amplifier MMICs is demonstrated, resulting in over 1 W of power at 140 GHz and 160 GHz, 400 mW at 195 GHz and 200mW at 230 GHz. A 260 GHz doubler driven by a 130 GHz 2-way combined amplifier is presented producing 100mW of power with less than 10 W DC power consumption.