High RF output power for H-terminated diamond FETs

We report great improvement of RF output power for H-terminated diamond field-effect transistors (FETs). For the FET device with a gate width of 1 mm and a gate length of 0.4 μm, the maximum output power (Pout) is 1.26 W, the maximum power gain is 23.2 dB, and the power added efficiency (PAE) is 56.3%. The increase in the device temperature when output power is 0.84 W is only ∼0.6 °C. This is due to diamond having the highest thermal conductivity.