A 1.9-GHz CMOS differential power amplifier for polar transmitter applications was implemented with a 0.25 mu m RF CMOS process. All of the matching components, input transformer, and output transformer are fully integrated with 50 Omega input and output matching. Each power transistor in each differential branch is split again and controlled separately to obtain a high power mode and a low power mode. The amplifier achieved a drain efficiency of 32% at the maximum output power of 29.5 dBm. The dynamic range is measured at approximately 275 dB with a supply voltage range of 0.7 similar to 3.3 V. (C) 2006 Wiley Periodicals, Inc.