Open AccessClass E Power Amplifiers using High-Q Inductors for Loosely Coupled Wireless Power Transfer System
Author(s) -
JongRyul Yang,
Jin-Wook Kim,
Youngjin Park
Publication year - 2014
Publication title -
journal of electrical engineering and technology/journal of electrical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.226
H-Index - 27
eISSN - 2093-7423
pISSN - 1975-0102
DOI - 10.5370/jeet.2014.9.2.569
Subject(s) - amplifier , rf power amplifier , power added efficiency , linear amplifier , electrical engineering , inductor , wireless power transfer , electronic engineering , direct coupled amplifier , power factor , engineering , power bandwidth , cascade amplifier , computer science , operational amplifier , voltage , cmos , electromagnetic coil
A highly efficient class E power amplifier is demonstrated for application to wireless power transfer system. The amplifier is designed with an L-type matching at the output for harmonic rejection and output matching. The power loss and the effect of each component in the amplifier with the matching circuit are analyzed with the current ratio transmitted to the output load. Inductors with a quality factor of more than 120 are used in a dc feed and the matching circuit to improve transmission efficiency. The single-ended amplifier with 20 V supply voltage shows 7.7 W output power and 90.8% power added efficiency at 6.78 MHz. The wireless power transfer (WPT) system with the amplifier shows 5.4 W transmitted power and 82.3% overall efficiency. The analysis and measurements show that high-Q inductors are required for the amplifier design to realize highly efficient WPT system.