An 18-GHz, 10.9-dBm fully-integrated power amplifier with 23.5% PAE in 130-nm CMOS

An 18-GHz fully integrated class-E power amplifier with 10.9-dBm saturated output power, and 23.5-% maximum PAE is fabricated in the UMC 130-nm digital CMOS process. At the saturated output, the required input power level is -5dBm and PA consumes 35mA from V_DD=1.5V. The amplifier is single-ended and includes a 2-stage pre-amplifier and a driver stage. A mode-locking technique exploiting the instability of driver amplifier is used to improve the drive for the gate of output stage. The mode-locking improves PAE by ∼3% and reduces the required input power level by ∼6dB to get same output level.