On the efficient wireless power transfer in resonant multi-receiver systems

In this paper we present an analysis of resonant wireless power transfer in systems with multiple receivers. We show that maximum power transfer can be achieved when the source is impedance matched to the set of receivers, i.e. matched to their equivalent impedance as seen by the source. The interaction of the receivers, or coupled modes, simply represent an interdependence of impedances that can be modeled and impedance matched. We explore three methods to achieve impedance matching: frequency tuning, impedance transformation and resonant tuning and show that the later two can achieve the maximum theoretical power transfer for a wide range of coupling between receivers.