Harmonic controlled three-way doherty amplifier with improved efficiency and linearity

In this paper the operation behavior of three-way Doherty amplifier loaded with harmonic control circuit is analyzed, including the efficiency and linearity. Amplifier is designed in configuration with two quarter-wave impedance transformers in the output combining circuit with LDMOSFETs in carrier and peaking amplifies in periphery relations 1:2.5:2.5. The signals for linearization: the fundamental signals' second harmonics-IM2 and fourth-order nonlinear signals-IM4 are extracted at the output of peaking cells suppressing the third-and fifth order intermodulation products of Doherty amplifier.