Class E And Inverse Class F Doherty Amplifier Design,

Power amplifier is one of the most important parts of such electronic equipments as communications, radar, and EW systems. There is sore need of high efficiency power amplifiers, not only so to cut the cost of electricity, decrease the investment of power supply equipments, but to reduce the requirement of cooling, increase the stability of equipments due to the decreace of power consuming and the simplicity of manufacture crafts.Switched-mode Amplifiers make very popular and attractive among high-efficiency PAs are being further studied. Class E, Class F, Class F^-1 as important switched modes are extensively studied in this paper.Power amplifiers employing Doherty architecture have the potential to deliver the efficiency demanded by transmitters. This letter reports gallium nitride HEMT Doherty power amplifiers based on Class E and Class F^-1 topology. For the proposed DPAs based on above topologies, the power added efficiencies are 61% and 58% with 23 dBm input power level, respectly. The experimental results confirm that the DPAs based on above topologies can be an attractive solution for high efficientcy PA design.Power combining methods is employed to increase the output power is basically limited by thermal and impedance matching problems of a single solid-state device. The aim of this paper is to give descriptions of the power splitting/combining structures, emphasizing their fundamental characteristics, properties and design process.