Common-Drain Flip-Chip GaAs FET Oscillators

GaAs FET oscillators with flip-chip mounted devices in a novel common-drain configuration are described. It is shown how common-drain oscillators can achieve low thermal resistance while at the same time minimizing parasitics. It is also shown that broad-band negative resistances can be generated without external feedback elements. This paper also reports experimental results where output powers of 390 mW with 22-percent efficiency at 8.5 GHz and 230 mW with 26-percent efficiency at 11.7 GHz have been demonstrated.