The objectives of workpackage 3 are twofold. First, suitable architectures of high-performance multibit oversampling D/A converters will be evaluated as a basis for the development of the models in workpackage 1, task 1.2. Second, the design of the demonstrators will lead to measurement results that shall be compared to the simulation results obtained by using the high-level models to explore the accuray of the new models. This report summarizes the results of the first task in which we have studied digital modulators as well as architectures for the implementation of the core D/A converters suited for highbandwidth telecommunciation applications.