Dynamic Model-Based Linearization of Quantized Pulse-Width Modulation for Applications in Digital-to-Analog Conversion and Digital Power Amplifier Systems

摘要

Quantized pulse-width modulation (PWM) offers an efficient means of converting digital data to analog either at low signal levels for DAC systems or at higher levels in power amplification. However, although a number of techniques exist, they are flawed by varying degrees of dynamic nonlinearity inherent to the conversion process, especially at lower sampling rates. The basic nonlinear mechanisms of PWM are described and a family of model-based solutions to the linearization problem is presented that retains the advantage of a uniform sampled digital format. As such it is possible to design PWM converters that exhibit vanishing levels of distortion even under broadband high-level signal excitation.