Relay Effects in Multiple-Node Resonant Inductive Coupling Wireless Power Transfer Systems

Resonant Inductive Coupling Wireless Power Transfer is a key technology to provide an efficient and harmless wireless energy channel to consumer electronics, biomedical implants and wireless sensor networks. However, current applications are limited to point-to-point links and do not explore the capabilities of Multi-Node Resonant Inductive Coupling Wireless Power Transfer Systems. In such a system, the multi-path relaying effect between different nodes could effectively improve the performance of the link in terms of power transferred to the load and power transfer efficiency. However, depending on the impedance and resonant frequency of the nodes that generate the multi-path effect, these nodes could also act as interfering objects, therefore a) making the transmitter and/or receiver act as a pass-band filter and b) loosing part of the transmitter magnetic field through coupling to the interfering node. In this article, a circuit-based analytical model that predicts the behavior of a Multi-Node Resonant Inductive Coupling link is proposed and used to perform a design-space exploration of the multi-path relaying effect in RIC Wireless Power Transfer Systems.