OTA Characterization of Nonlinear Transmitters Using Specially Designed Multi-Sines
5G mMIMO approaches will impose very large active antenna arrays, most of these arrays consist of a combination of active antenna elements that will have the total power combined in space (over-the-air). Nevertheless each of these paths are highly nonlinear since they contain a power amplifiers in the RF path, and thus the constellation diagram and the impact of each element in its neighbor can change completely the transmitter original design and OTA configurations. In this talk we will address OTA behavioral characterization and modelling for active antenna arrays consisting on active nonlinear elements, using special designed multi-sine excitations. Some practical examples will also be discussed and presented including the using of laboratory equipment set-ups for implementing the proposed solution.