A Novel Single-RF Outphasing MIMO Architecture

A novel single-RF multiple-input multiple-output transmitter architecture based on the outphasing principle is presented. An efficient switching amplifier feeds a tunable analogue network with the unmodulated carrier. The carrier is then modulated utilising the outphasing principle and distributed to the antennas. Featuring only a small set of standard RF components - namely power splitters, phase shifters, and hybrid couplers - the structure can be readily implemented in a costefficient, passive integration manner. Various modulation schemes for the architecture are investigated including the particular power efficient phase shift keying on the hypersphere. Our numerical results show that the proposed architecture is a power- and cost-efficient solution for multi-antenna transmitters on energy-limited user devices.