Apparatus and method for phase synchronization in radio frequency transmitters

摘要

Apparatus and methods are disclosed related to phase synchronization in transmitters. One such apparatus includes a wireless transmitter with two or more separate and unrelated local oscillators. The apparatus can provide RF signals to multiple antenna elements, which can be implemented in systems such as beamforming systems or multiple input multiple output (MIMO) systems. A phase difference between local oscillators is determined using outputs of receivers. The phase difference can be used to adjust a phase of signals associated with one or more of the local oscillators, such that the phase of each signal provided to the multiple antenna elements can be aligned.