Bounds for optimization of the reflection coefficient by constrained optimization in hardy spaces

The purpose of this book is twofold. Our starting point is the design of layered media with a prescribed reflection coefficient. In the first part of this book we show that the space of physically realizable reflection coefficients is rather restricted by a number of properties. In the second part we consider a constrained approximation problem in Hardy spaces. This can be viewed as an optimization problem for the frequency response of a causal LTI system with limited gain.