Optimised Doherty power amplifier with auxiliary peaking cell

The Doherty power amplifier has the most attractive architecture to improve the efficiency for amplifying a signal with a high peak-to-average power ratio. However, the ideal Doherty operation is difficult to be achieved because the g_m of the peaking amplifier should be two times larger than that of the carrier amplifier. The g_m mismatch between the carrier and peaking amplifiers hinders the proper load modulation at the peak power region. The Doherty power amplifier with an auxiliary drive cell for the peaking amplifier is introduced to solve the problem. The auxiliary peaking cell drives the main peaking amplifier with higher input power, solving the gain and output power reduction problem. Experimental results show that the proposed Doherty power amplifier can enhance gain, output power and power-added efficiency.