Discrete spurious signals and background noise in direct frequency synthesizers

Some sources of output spurious signals in direct digital frequency synthesizers are discussed. First, the authors provide a closed-form solution for spurious signals generated by phase truncation. Then they consider the accuracy of sine look-up tables and arrive at an estimated level of background spurious signals generated this way. They also investigate the behavior of digital-to-analog convertors and their bit resolution, nonlinearity, and clock signal leakage. Finally, they investigate the eventual phase noise level.