A 10 W Multi-Mode Capable Wireless Power Amplifier for Mobile Devices

There are currently 3 wireless power standards for the mobile device market: the Wireless Power Consortium (Qi) standard [1], the Power Matters Alliance (PMA) standard [2] and the Alliance for Wireless Power (A4WP) standard [3]. Recently PMA and A4WP merged to become known as AirFuel(TM). The proliferation of wireless power products for mobile applications is leading to consumer confusion and hindering adoption of this technology [4]. A simple eGaN© integrated circuit based, single amplifier topology capable of operating to all of the mobile device wireless power standards is presented. It uses a modified ZVS class D amplifier topology capable of operating at both high (6.78 MHz) and low frequencies (100 kHz through 315 kHz). In addition, a specially designed source coil that can be used for all the wireless power standards is presented. The amplifier and source coil together allow for true multi-mode capable wireless power transfer that will be experimentally verified to both the AirFuel class 2 [5] and Qi/PMA [1, 2] standards and are designed for mobile phone charging applications.