An Armstrong GaN-Based Oscillator for Wireless Power Transfer Applications

This paper reports the design and implementation of an Armstrong power oscillator for wireless power transfer (WPT) using GaN HEMT (high electron mobility transistor) at 4.6 GHz and GaN FET at 40 kHz. In the first design, a low power depletion-type device is used, simulated and integrated with a magnetically coupled resonant (MRC) WPT system using PCBs. The second design is based on a higher power enhancement-type transistor, where it is simulated and compared with the first design. High quality AC output waveforms with low distortion are obtained, which leads to low electromagnetic interference (EMI) levels that are required for sensitive applications such as biomedical technologies.