Adaptive feedforward control of a high-power amplifier powered by noisy power supplies

Radiofrequency power amplifiers (PA) are subject to constraints on their output ripple in demanding applications. Vacuum tube-based power amplifiers are a very cost-effective and durable solution when supplied by diode or thyristor rectifiers. However, they are more susceptible to this constraint. A feedback loop can significantly reduce ripple caused by noisy power supplies, without the need for bulky and expensive filters. However, this may not be sufficient. As demonstrated in this paper, incorporating an adaptive feedforward function can effectively reduce ripple without the need for additional analogue components, while maintaining a relatively simple numerical complexity.