Some Key Aspects of Near-Field Wireless Power Transfer Technologies for High Frequency, High Power, and High Efficiency

Existing wireless power transfer (WPT) applications and standards mainly rely on sub-Mega-Hertz operations and their power level generally decreases with operating frequency. Many emerging WPT applications have limited charging areas and prefer higher frequency operation for fast charging with improved energy efficiency. With the new recommendations by the International Telecommunication Union on the use of Mega-Hertz frequency bands for non-beam WPT applications, it is imperative to explore new high-frequency WPT technologies. This paper presents the hurdles and possible solutions to the uncharted area of high-frequency (MHz), high-power (kW) and high-efficiency (>95%) WPT technologies. For 1M Hz - 13.56 MHz operation, the technical hurdles include (i) resonator designs suitable for mass production, (ii) ultrafast gate drive designs, (iii) power inverters with soft switching, and (iv) electromagnetic shielding methods for Mega-Hertz WPT applications. Existing solutions and emerging technologies for overcoming the hurdles in these four key aspects of WPT are addressed. © 2025 The Authors. This work is licensed under a Creative Commons Attribution 4.0 License.