New Output Combiner for Doherty Amplifiers

In this letter, a new output combining network for the implementation of a Doherty Power Amplifier (DPA) is presented. The proposed topology simultaneously allows the active load modulation and the output matching, by adopting more realizable elements than the standard DPA, especially when high output power levels are required. The innovative design approach is demonstrated through a practical prototype realization based on GaN-HEMT devices. Experimental results have shown a 65%-48% efficiency at about 42-36 dBm output power with a gain compression lower than 1.5 dB from 1.95 to 2.25 GHz.