NEW HIGH-ACCURACY PULSE-WIDTH MODULATION BASED DIGITAL-TO-ANALOG CONVERTER POWER-AMPLIFIER

A new high accuracy pulse width modulation based digital-to-analogue c onvertor is presented. It is suitable for high power applications as w ell as ordinary low power use. While possessing important advantages, previously proposed convertors of this type have been difficult to rea lise in hardware and/or have exhibited high distortion. In this paper, digital signal processing (DSP) techniques are used to facilitate har dware implementation and increase performance. Specially designed over sampled noise shaping networks allow reductions in internal modulator clock speed large enough to make a 16 bit quality implementation possi ble. Also, new premodulation, predistortion DSP algorithms of varying complexity and accuracy are employed to reduce the harmonic distortion inherent to the modulation process typically used. Computer simulatio ns are presented to verify the improvements.