LINEARIZED SWITCH-BASED POWER AMPLIFIER

摘要

The invention relates to a power amplifier comprising a level-discretization modulator (210) and a mixing and amplifying stage (225), in combination with a properly designed negative feedback path. The feedback path forms an error compensation loop together with a properly selected forward path. The forward path includes at least the mixing and amplifying stage (225), which provides frequency up-conversion to the radio frequency band and switch-based amplification. The negative feedback path includes a down-conversion mixer (280) for down-conversion to the initial frequency band, and compensates for distortion caused by components of the forward path. The negative feedback action will generally reduce both distortion caused by non-linear steady state impedance of the switches as well as distortion caused by non-linear steady state impedance of the switches as well as distortion resulting from switching glitches. Preferably, the level-discretization modulator (210) used by the power amplifier is also included in the forward path of the loop so that the feedback path compensates for distortion, such as quantization noise, caused by the modulator.