This paper presents a novel dual-input Doherty-Outphasing Power Amplifier (DOPA) architecture that combines the efficiency advantages of Doherty and Outphasing amplifiers in power back-off (PBO). The proposed architecture, utilizes Doherty operation from peak power to -6dB PBO and mixed-mode outphasing from -6 to -14 dB PBO. A 2.14 GHz 112W GaN DOPA has been designed to demonstrate the concept, it provides 66% peak efficiency and more than 50% efficiency over a 12 dB PBO range.