A GaN-on-Si MMIC Doherty Power Amplifier for 5G Applications

This contribution presents the design of a two-stage Monolithic Microwave Integrated Circuit (MMIC) Doherty power amplifier (DPA) for 28 GHz 5G applications. The circuit is realized on a novel Gallium Nitride on Silicon (GaN-Si) technology with 100 nm gate length. Accounting for the peculiarities of the selected technology, especially the lossy substrate, effective circuital solutions to optimize the overall DPA performance are proposed and applied to finalize the chip layout. Expected performances at 28GHz are about 13 dB, 35% and 2W of gain, efficiency and saturated output power, respectively. To the best of authors' knowledge, this is the first implementation of a DPA at millimetre wave on GaN-Si technology.