A class-S RF amplifier architecture with envelope delta-sigma modulation

This paper proposes a new architecture to realize a class-S RF amplifier working at high carrier frequency. The existing class-S RF amplifier has the potential to achieve high efficiency while the highest RF frequency it can handle is determined by the switching speed of delta-sigma modulators. Due to the current technology limit of digital circuits, the approach is difficult to implement for amplifiers above the gigahertz frequency range. The proposed approach can overcome this difficulty by sampling the signal envelope with the delta-sigma modulator rather than the original carrier, which is more promising in practical implementation.