An implementation of a dynamic supply RF power amplifier (PA) in 0.11 mu m CMOS technology occupying a total area of 1.35mm(2) is presented. Two-tone measurement results at 2.4 and 5.2GHz show that the system can deliver over 16dBm linear output power with efficiencies of 22.7% and 12.6%, respectively. Compared to constant supply operation, besides providing higher linear output power, the dynamic supply technique allows over 230% relative efficiency enhancement at 2.4GHz and 160% at 5.2GHz at low output power levels. OFDM measurements at 2.4GHz demonstrated that at 3% Error Vector Magnitude (EVM) the absolute improvement in efficiency is over 1.5%.