  In this paper sensitivity minimization problem is considered for a class of
unstable time delay systems. Our goal is to find a stable controller
stabilizing the feedback system and giving rise to smallest H-infinity norm for
the sensitivity function. This problem has been solved by Ganesh and Pearson
(1986) for finite dimensional plants using Nevanlinna-Pick interpolation. We
extend their technique to include possibly unstable time delay systems.
Moreover, we illustrate suboptimal solutions, and their robust implementation.
