New high accuracy pulse width modulation based digital-to-analogueconvertor/power amplifier

摘要

A new high accuracy pulse width modulation basedndigital-to-analogue convertor is presented. It is suitable for highnpower applications as well as ordinary low power use. While possessingnimportant advantages, previously proposed convertors of this type havenbeen difficult to realise in hardware and/or have exhibited highndistortion. In this paper, digital signal processing (DSP) techniquesnare used to facilitate hardware implementation and increase performance.nSpecially designed oversampled noise shaping networks allow reductionsnin internal modulator clock speed large enough to make a 16 bit qualitynimplementation possible. Also, new premodulation, predistortion DSPnalgorithms of varying complexity and accuracy are employed to reduce thenharmonic distortion inherent to the modulation process typically used.nComputer simulations are presented to verify the improvements