An Efficient Noise-Shaping Architecture for Wideband Applications

In this paper a new optimized multi-stage (Delta-Sigma) structure is proposed. The method combines the reduced-sample-rate architecture with the optimization of the zeros of the noise transfer function ( ). To achieve this, the first stage of the decimation filter has to be modified as well. Applying this method one can avoid the loss introduced by using the reduced-sample-rate second-stage. The can actually increase for higher-order structures. Simulation results for a 2-0 MASH structure with an oversampling ratio of 4 are shown to verify the technique.