Three-Way Doherty Power Amplifier Using Class-F Amplifier for More Efficient Mobile Communications

Abstract

An efficient three-way Doherty amplifier is designed and simulated using Cadence Microwave Office software. 6W, 25W and 45W GaN HEMT transistors are used to design three-way Doherty amplifier at 3.4-3.8 GHz band to achieve a 76W peak power. Each amplifier was designed to work as a class F amplifier to improve the efficiency of the designed amplifier. In addition, A new configuration of impedance modulation is used, where a 12.5 dB gain was obtained over the band, in addition, a 13 dB back-off efficiency was achieved with 50-60% drain efficiency. Changing the location of the peaking amplifier or changing the operation sequence of the peaking amplifier can achieve good efficiency at the back-off region. There was an efficiency improvement of 10% at the back off by utilizing a class F amplifier comparing with the classical Doherty design.