yEd is a multi-purpose diagram editor for node-link diagrams. This allows the creation of different types of diagrams, e.g. by adding custom node visualizations/icons.
I'm not entirely sure what kind of diagrams you mean by "Impulse Diagram". Looking through Google results, there are quite different understandings of the term.
Anyhow, there is no plugin or mode dedicated to the creation of certain types of diagrams that you could enable.