500 MHz OOK Transmitter With 22 pj/bit, 38.4% Efficiency Using RF Current Combining

A 500 MHz On-Off Keying (OOK) transmitter integrated with a high-efficiency wideband power amplifier (PA) is designed for low-power/high-data rate applications. The PA biased in Class C region, employs a bias current-reused and an RF current-combining structure to achieve a high-efficiency and high-data rate. The transmitter is fabricated using a 0.13 μm CMOS process. The chip size is 0.6 mm² and the measured drain efficiency of the PA reaches 59.5% at 500 MHz with 1.62 dBm output power while consuming only 2.52 mW dc power from a 3 V power supply. The efficiency of the transmitter is 38.4% and the energy usage is 22 pJ/bit at a data rate of 100 Mbps with -0.75 dBm average output power.