Description
Wide-bandgap GaN and SiC power devices have enabled highly efficient RF power electronics operating at elevated switching frequencies, voltages, and temperatures. Combined with optimized circuit design, these devices allow operation beyond the regimes originally specified by their manufacturers. Their availability as low-cost commercial components supports the New Space approach, facilitating the rapid development and iterative optimization of RF power systems for space electric propulsion without the need for specialized electronics. As the performance of semiconductor switching devices continues to improve, the dominant limitations increasingly shift to the magnetic components. This work investigates the optimization of magnetic components in a Class-E RF power amplifier operated at a fixed frequency and constant power delivered to a load. Following electrical tuning, the amplifier is intended for inductively coupled plasma generation. The study focuses on the RF choke, resonant inductor, and matching network inductor, whose magnetic losses and thermal behavior largely determine the overall amplifier efficiency in vacuum conditions. A major challenge is that commercially available magnetic materials are typically characterized under operating conditions that differ substantially from those encountered in high-frequency power amplifiers. Consequently, reliable material selection requires experimental evaluation under realistic electrical, thermal, and high-frequency operating conditions rather than relying solely on manufacturer specifications. The first stage of this work therefore compares selected ferromagnetic and ferrimagnetic cores through thermal characterization during operation in ambient air, providing a rapid and cost-effective screening method before vacuum testing. The proposed methodology combines the selection of state-of-the-art commercially available semiconductor switching devices, simulation-based optimization of the electrical design, and experimental evaluation of magnetic components under representative RF operating conditions. This approach provides a practical pathway toward the development of an optimized Class-E RF power amplifier suitable for subsequent testing with inductively coupled plasma generation.
Funding from the Internal Scientific Grant System of UPJŠ (VVGS-2025-3813) is acknowledged.