Increasing the performance of arbitrary waveform generators using periodic sigma-delta modulated streams

Abstract

This paper describes a new method to increase the performance of existing arbitrary waveform generators (AWGs). By encoding the digital words using sigma-delta (/spl Sigma//spl Delta/) techniques, it is possible to decrease the noise floor in a narrow band while keeping the same memory requirements. Calibration techniques to deal with the nonidealities of the AWG are also presented and verified experimentally. Improvements in spurious free dynamic ranges (SFDRs) of over 40 dB will be demonstrated with commercial test equipment.