A high efficiency Ka-band monolithic GaAs FET amplifier

摘要

A monolithic three-stage Ka-band GaAs FET power amplifierhas been designed and fabricated on MBE (molecular-beam epitaxy)-grownmaterial with a highly doped (8×1017 cm-3)channel. Devices with gate length of 0.25 μm and gate width of 50μm, 100 μm, and 250 μm were cascaded. The gate and drain biasnetworks were also integrated. A maximum small-signal gain of 26 dB wasobtained with 4 V on the drain and 0 V on the gate. When biased forlarge-signal operation, the amplifier was capable of generating 112 mWoutput power with 16-dB gain and 21.6% power-added efficiency at 34 GHz.It is believed that this is a record efficiency for a GaAs MMIC(microwave monolithic integrated circuit) amplifier at this frequency