Research and design of Doherty power amplifier used in base station

To deal with the efficiency and linearity of PA in base station, the Doherty amplifier structure is adopted in this paper, and we solve this problem successfully via load-pull design technique in ADS platform. A balanced amplifier and a Doherty amplifier have been designed. They are applied in the frequency range of 1930-1990MHz for base stations. We make a comparison of the power added efficiency and third-order inter-modulation distortion, through the simulation we can draw a conclusion that the Doherty power amplifier´s efficiency can reach 30.4%, increasing 4% compared with the balanced amplifier, 12.6% compared with the AB amplifier. The 3rd order inter-modulation distortion can go down to below -20dBc. Doherty amplifiers have been demonstrated high efficiency and good linearity, on the basis of the pre-distortion linearization, the amplifier can be well applied to the base station system. This method improves system performance and has important reference value to designers engaged in PA.