Surface-wave analysis of a magnetic field wireless power transfer system operating over real/imperfect ground

Magnetic field wireless power transfer (MF-WPT) systems for the charging of hybrid and electric vehicle batteries constitute an emerging technology and one which is being rapidly standardized by several international organizations such as IEC, JARI and SAE. Recent global harmonization efforts tend to favor a fundamental charging operation centered at frequencies around 85 kHz, which lies in the LF frequency range. The attendant wavelengths, on the order of 3.5 km, would seem to preclude the radiation of any significant power by a single such system, at least at the fundamental frequency.