On the mixed sensitivity minimization for systems with infinitely many unstable modes

In this note we consider a class of linear time invariant systems with infinitely many unstable modes. By using the parameterization of all stabilizing controllers and a data transformation, we show that ℋ ∞ controllers for such systems can be computed using the techniques developed earlier for infinite dimensional plants with finitely many unstable modes. © 2004 Elsevier B.V. All rights reserved