Design of a dual-band GaN Doherty amplifier

In this paper, the design, realization and test of a dualband Doherty power amplifier (DPA) will be presented. The design has been realized in hybrid technology using a packaged GaN HEMT as active devices. A special attention will be focused on the passive structures involved in the DPA design (input power splitter, impedance transformer network, impedance inverter network and phase compensation network) showing several possible implementations and the related tricky aspects. The DPA has been designed to operate simultaneously at 2.14GHz and 3.5GHz with 6 dB of output power back off (OBO) at both frequencies.