Spectral features of ZVD shapers with lumped and distributed delays

An interesting spectral property, related to sensitivity of ZVD shaper zeros with respect to small deviations of involved delays, is presented in the paper. Consequences concern namely feedback interconnections as indicated in the report. Compared to the lumped-delay case, the recently proposed distributed delay alternative - ZVD shaper with distributed delay - is a more robust option, as explained and demonstrated by means of roots diagrams. Several examples are presented to demonstrate the phenomena.