Near field, full duplex data link for use in static and dynamic resonant induction wireless charging

A full duplex, low latency, near field data link controls a static and/or dynamic resonant induction, wireless power transfer system used for recharging electric vehicles and other electrically powered devices. A coherent transponder configuration enables low complexity synchronous detection and positive rejection of signals originating from nearby and adjacent vehicles. A reference crystal oscillator in the ground side apparatus provides frequency synchronization for both the forward and the return data links. Transmission is by means of near field magnetic induction between pairs of loop antennas which, together with the effective waveguide below cutoff structure comprised by the vehicle underbody and the ground surface, largely restrict signal propagation to the area in the immediate vicinity of the system antennas.