Designing an Efficient Amplifier for a Wireless Power Transfer System

Efficient Power Conversion Corporation announced the publication of a practical engineering handbook designed to provide power system design engineers valuable experiences and points of reference critical to understanding and designing highly efficient wireless power systems using gallium nitride-based transistors. As a supplement to EPC’s GaN Transistors for Efficient Power Conversion, this new practical guide provides step-by-step analysis on the use of GaN transistors in wireless power transfer.  

Highly resonant wireless power transfer using eGaN FETs has proven to be a viable path to efficient, convenient wireless power. The use of magnetic fields contributes to ease of use and robustness, but most importantly, it is considered safe. However, the implementation of this technology poses many challenges to power system designers. At the heart of highly resonant wireless power is the amplifier, which drives the coils that generate the magnetic field. eGaN FETs have, in part, driven the wireless power revolution by offering high efficiency, robustness to operating conditions and are easy to use. This handbook addresses the many design aspects needed for a wireless power transfer system. Topics covered include how to effectively compare component devices, such as eGaN FETs and MOSFETs, when used in an amplifier design. This comparison, complete with experimental verification, illustrates the superiority of eGaN FETs over MOSFETs. Wireless power solutions rely on ease-of-use for consumer convenience and eGaN FET performance ensures that the requisite challenges associated with ease-of-use can be met using the simplest and most cost-effective solutions. 

Alex Lidow, Efficient Power Conversion CEO points out that, “Magnetic field technology may have caught up with the concept of wireless power, but the implementation poses many challenges to power system designers. Based upon experimental results, this handbook shows that the ZVS Class D topology, fitted with eGaN FETs, exhibited superior performance as compared to the other amplifiers.” 

About EPC

EPC is the leader in enhancement mode gallium nitride based power management devices and was the first to introduce enhancement-mode gallium-nitride-on-silicon (eGaN) FETs as power MOSFET replacements in applications such as DC-DC converters, wireless power transfer, envelope tracking, RF transmission, power inverters, remote sensing technology (LiDAR), and class-D audio amplifiers with device performance many times greater than the best silicon power MOSFET