High-efficient class F GaAs FET amplifiers operating with very low bias voltages for use in mobile telephones at 1.75 GHz

High-efficiency class F GaAs power FET amplifiers working with a very low drain bias voltage of 3 V, for use in portable telephones, are reported. The transistor used has an optimized gate periphery of 2000 mm and a gate length of 0.7 mu m. Under class F operation with a drain voltage of 3 V, it has demonstrated an output power of 24.5 dBm with 71% of power-added efficiency at the operating frequency of 1.75 GHz. Output harmonic levels lower than -25 dBc have been measured. The results obtained present the state of the art as published for low-bias-voltage, low-power-consumption amplifiers for mobile telephone systems.<>