Recently DDS (direct digital synthesis) based function generators have been developed into arbitrary/function generators with impressive specifications.

However, the DDS approach to arbitrary waveform generation imposes serious limitations which are not immediately obvious.

The alternative approach of a variable clock architecture offers a greater level of flexibility and can be used to solve many more real-world problems.

Some manufacturers, who offer both types of generator, refer to DDS arbitrary generators as AFGs (arbitrary function generators) and to variable clock generators as AWGs (arbitrary waveform generators).  Other manufacturers give no indication of the technology used for arbitrary waveform generation.

Before purchasing a generator intended for arbitrary waveform use,

                                                                      it is important to discover which technology it uses.