Time reversed electromagnetic wave propagation as a novel method of wireless power transfer

We investigate the application of time reversed electromagnetic wave propagation to transmit energy to a moving target in a reverberant environment. “Time reversal” is a signal focusing method that exploits the time reversal invariance of the lossless wave equation to focus signals on a small region inside a complex scattering environment. In this work, we explore the properties of time reversed microwave pulses in a low-loss ray-chaotic chamber. We measure the spatial profile of the collapsing wavefront around the target antenna, and demonstrate that time reversal can be used to transfer energy to a receiver in motion. We discuss the results of these experiments, and explore their implications for a wireless power transmission system based on time reversal.