Multi-stage noise band cancellation ΣΔ modulator for digitisation of distorted signals
Résumé
A new sigma-delta modulator (ΣΔM) architecture is proposed to digitise wideband distorted signals. It combines frequency band decomposition with bandpass (BP) ΣΔ converters and cascaded architectures. The novelties are the use of the residual signal transfer function at the output of the first summing node in a classical BP ΣΔ that is an almost free signal shaping in the ΣΔM and the digitisation of the shaped noise in order to cancel it out in a particular band.