Class-E CMOS power amplifiers for RF applications

CMOS radio frequency class-E power amplifiers (PA) for GMSK/GFSK modulations have been designed and fabricated using 0.25/0.35/spl mu/m technologies. The operating frequencies are centred at 1.2GHz and 2.65GHz with 24-26dBm output power. Mode locking techniques are employed for both designs, in order to reduce the driving requirement. High efficiency broadband off-chip hybrid ring baluns are used at both input and output for converting signals from single-ended to differential and vice versa. Regular bonding wires are used as inductors for the 1.2GHz PA, and on-chip bondwires are used for the 2.65GHz PA. With a 1.3V supply, the measured power added efficiency (PAE) of the 1.2GHz PA, after taking into account the losses in the baluns, is 62%. The PAE for the 2.65GHz PA is 38% when operated from a 1.7V power supply.