A Very High Frequency Self-Oscillating Inverter Based on a Novel Free-Running Oscillator

This paper introduces a self oscillating very high frequency (VHF) class $\phi 2$ inverter based on a free-running oscillator. The class $\phi 2$ is a low voltage semiconductor stress, fast transient, single transistor inverter topology suitable for very high frequency applications. With new advancements in GaN technology, the tendency to increase the switching frequency in power converters is on the rise. Switching at very high frequency (VHF: 30MHz-300MHz) allows for smaller passive components and more compact power converters. However, although GaN components are able to switch at 100 MHz and beyond, gate drivers available in the market struggle to provide the adequate switching signal at very high frequency. Hence, there is a need for an alternative to VHF converters using those gate drivers : self-oscillating topologies. To that end, a self-oscillating class $\phi 2$ inverter switching at 30 MHz is presented and a design methodology is provided. A 30MHz prototype with 30V input voltage using a GaN Systems GS61004B is also built and tested, showing good matching between the simulation and experimental results.