Characterization and Modeling of Dual-Input Doherty Power Amplifier for High Efficiency and Bandwidth

This paper presents the improvement, in terms of efficiency, that can be achieved by a dual-input Doherty Power Amplifier (DPA) in relation to the more classical single-input configuration. The better results obtained from the dual-input solution are intrinsically connected to the independent control of the two inputs in terms of power and phase. In particular, above the power backoff point, the degree of freedom given by the control of the phase difference between the inputs allows one to operate in a condition of maximum efficiency at any output power level. To test the board and validate the results, a dedicated experimental setup for the characterization of the amplifier has been designed and realized. As will be demonstrated, the efficiency of a dual-input DPA is considerably improved compared to the single-input configuration.