Enhanced TED MMW Device Performance using Graded Doping Profiles

Epitaxially grown GaAs transferred electron device n++n n+ structures, having intentionally graded n-active layer doping concentrations, exhibit significant improvements in output powers and efficiencies relative to flat n-active layer devices. A further improvement of greater than 30 percent results for devices designed to operate in the heat sink - anode configuration. state-of-the-art rf performance results are presented here along with accelerated life test date: oscillators operating continuously (cw) at 110°C near 61GHz in the second harmonic mode have exhibited essentially constant rf and dc performance after 10,000 hours of operation. Extrapolation to +85°C corresponds to 50,000 hours (5.7 years).