Broadband High-Frequency Power Modulation With Resistance Regulation Network

Efficient radio frequency (RF) power amplifiers (PAs) are essential in various industrial applications, where fast RF pulses are often required to enhance system performance. In this article, we present a novel approach to fast RF power modulation using a resistance regulation network (RRN) with frequency adjustment. The proposed method is complementary to existing systems and can be adapted to a wide range of power and frequency levels. To illustrate the general design methodology of the RRN, we use an inductively coupled, double-tuned network as an example. We also discuss its loading effects and provide design guidelines for broadband switched-mode PAs. A 300 W class-$\Phi _{2}$ amplifier with RRN is implemented and tested, achieving a peak efficiency of 94%. Operating between 13.2 and 14.4 MHz, the amplifier is capable of doubling its output power within 500 ns while maintaining zero-voltage-switching (ZVS).