WPT (Wireless Power Transfer) or WET (Wireless Energy Transfer) refer to methods to transfer electrical energy without the use of a physical link. Instead a varying electromagnetic field is used to couple energy from a transmitter to a receiver. Several ISM frequencies are being used for this work.
While this is not a new technology, it was demonstrated by Tesla in the early 1900’s, it has recently become very active in the advent of electric vehicles. E&I’s S-Series of amplifiers are well suited to the resonate-coupled approach for near field transfer that operates in the low KHz region.