Doherty type high power amplifier with 33% efficiency

This work describes the design of a two-way Doherty type Power Amplifier, using LDMOS transistors, for base station wireless transceivers in the frequency range of 2.5-2.7 GHz. Two of the main requirements of this amplifier are high efficiency and good linearity, which are always in conflict. The Doherty configuration, composed of a main amplifier and a peaking amplifier offers a reasonable tradeoff between the two requirements. A prototype amplifier based on simulations has been built and tested, including the transistors characterization. Efficiency of 33% over the full band of frequencies, with good linearity till output power of 42 dBm has been demonstrated.