In 1819. H.C. Oersted found that electric current generates a magnetic field around it. Later in 1864, James C. Maxwell predicted the radio waves. The transfer of power was first experimented by using radio waves as a medium. Then, he introduced how electric and magnetic fields are generated and changed by one another. They built a foundation for the modern theory of electromagnetism. In 1888, Heinrich Hertz proved the existence of electromagnetic radiation by transmitting electricity over a small gap by using oscillator connecting with induction coils. However, Nicola Tesla was the first one to have experiments of wireless power transfer on microwave technology. His major breakthroughs included transfer of microwave signals over the distance of 48 km in 1986 and transmitted 10 volts of high-frequency electric power to light up 200 bulbs and run an electric motor in 1899. He then introduced Tesla coil and built the Wardenclyffe Tower to transfer electric energy without cords via Ionosphere. But this experiment failed because of technology limitation.Until 1964,, W.C. Brown converted microwaves to electricity through a rectenna. It inspired later innovations of microwave-powered airplanes in Japan and Canada in the 1980s and 1990s.· In the 1990s, wireless charging product surged due to the popularity of portable electronic device. Far-field and near-field wireless charging were progressing. In 1971, Professor Don Otto of the University of Auckland introduced an inductively power trolley model. In 1978, J.G. Bolger, F.A. Kirsten, and S. Ng designed a electric vehicle charged with a system, the first application of inductive charging in the U.S.· In 2006, MIT made a key breakthrough of inductive charging that they used resonant coupling to transfer power without radiation over a small distance.· Most recently, Wireless Power Consortium, Power Matters Alliance and Alliance for Wireless are founded to establish international standards for wireless charging. They are widely adopted in electronic products in the markets.