Switched-Mode Power Amplifiers from 3 to 300 MHz: Design and Exploration

Abstract: (This webinar is sponsored by PELS TC 1.) Switched-mode power amplifiers operating in the 3-300 MHz range are essential for applications such as plasma generation, wireless power transfer, and radio-frequency heating. Achieving wide operating ranges—including resistive and reactive loads, and varying power levels—while maintaining high power and high efficiency presents significant design challenges. Zero-voltage switching (ZVS) is crucial at high frequencies to minimize switching losses, but ensuring ZVS across a wide range of conditions requires careful design trade-offs. In this seminar, we will explore several switched-mode power amplifier topologies: current-mode class D power amplifiers demonstrated at 100 MHz and 6.78 MHz for wireless power transfer, a single-stage wide-range voltage-mode class D power amplifier demonstrated at 13.56 MHz for plasma generation, and a three-phase current-mode class D power amplifier. We will investigate their ZVS conditions and discuss strategies to achieve wide-range, high-power, and high-efficiency operation while overcoming key design trade-offs. The 3-300 MHz power conversion and wireless transmission domain remains largely unexplored, including materials, power, control, electronics, and electromagnetics, offering vast opportunities for innovation. As this field continues to evolve, there is great potential for researchers and engineers to pioneer new solutions and unlock its full capabilities.