A 28 GHz MMIC Doherty Power Amplifier in GaN on Si Technology for 5G Applications

This contribution is focused on the experimental characterization of a Doherty Power Amplifier (DPA) realized on a 100 nm gate length Gallium Nitride on Silicon (GaN-Si) technology for 28 GHz 5G applications. The DPA is based on a two-stage symmetric architecture, resulting in a 3 x 2 mm
²
chip area. When measured in continuous wave and at 28 GHz the chip achieves a saturated output power of 32 dBm with a gain of 13 dB and a power added efficiency close to 30% in a 6 dB of output power back-off. Such performances remain almost constant in a bandwidth larger than 1 GHz.