Linearization of two-way Doherty amplifier by injection of second and forth order nonlinear signals at the input and output of the carrier cell

In this paper two-way Doherty amplifier with the additional circuit for linearization has been realized and measurements of the linearization influence to the third - and fifth-order intermodulation products have been carried out. The linearization approach uses the fundamental signals´ second harmonics and fourth-order nonlinear signals that are extracted at the output of the peaking cell, adjusted in amplitude and phase and injected at the input and output of the carrier cell in Doherty amplifier.