2.1 Times increase of drain efficiency by dual supply voltage scheme in 315MHz class-F Power amplifier at output power of −20dBm

Dual power supply voltage (V_DD) scheme is proposed to increase the efficiency of a power amplifier (PA) with small output power (P_OUT) for short-range wireless sensor networks (e.g. body area networks). At P_OUT of -20dBm, compared with the conventional single V_DD PA, the drain efficiency (DE) and the global efficiency (GE) of the proposed dual V_DD PA increase by 2.1 times and 1.5 times, respectively. A class-F PA fabricated in 40-nm CMOS with the proposed dual V_DD (0.2V and 0.56V) achieves the highest DE of 42% at P_OUT of -20dBm in the published PA´s. The PA is applied to a 315MHz OOK transmitter (TX) and the TX achieves the highest GE of 28% at P_OUT of -20dBm and the lowest energy of 36pJ/bit (= 36μW@1Mbps) in the published TX´s.