Based on theory which can improve efficiency effectively of Doherty

this paper analyses the existing problems of 2-way asymmetric Doherty at first

then presents a novel 3-way Doherty structure that embeds a conventional Doherty inside.Theoretical analysis and detailed description of the working state as well as impendence transformation of the proposed Doherty are given.Finally

combining multi-harmonic bilateral pull technology and the dual match technology

a 3-way Doherty amplifier with 5W average power is designed for TD-LTE repeater application.The 2600 MHz simulation results of the 3-way Doherty yielded-36dBc 3rd-order intermediation(IMD3)

10.6 dB power gain(Gp)

with 56% power added efficiency(PAE) which is 38% higher than class B amplifier at average output power.Moreover

the curve among 12 dB back-off power is smooth relatively.On the one hand

this will answer the purpose of high power back and high efficiency.On the other hand

it lay the foundation for combination of the digital predistortion technique for repeater application.