Effect of Oscillator Jitters on Distributed Energy Beamforming for Wireless Energy Transfer

In wireless energy transfer (WET), distributed energy beamforming is promising to solve energy scarcity problem while to alleviate potential health and safety problems. In this letter, we investigate the effect of oscillator jitters on distributed energy beamforming in a multiple-input-multiple-output (MIMO) WET system where both carrier frequency offset (CFO) and phase noise (PHN) are considered. We theoretically derive the ratio of energy loss because of oscillator jitters and its upper bound. It is found that the upper bound on the ratio of energy loss is not related with distributed MIMO channel and distributed energy beamforming. Simulation results demonstrate that the ratio of energy loss because of PHN and CFO increases almost linearly and quadratically with the increase of block duration, respectively.