Gain Margin Improvement Using Generalized Sampled-Data Hold Functions

This paper considers the gain margin problem of a linear time-invariant plant controlled by a memoryless generalized sampled-data hold function (GSHF) with output feedback. It is proved that arbitrarily large gain margin can be achieved by suitable selection of sampling time and the GSHF hold. We use state space methods and give a constructive design procedure. The controller we use is memoryless in the sense that the closed-loop system has the same McMillan degree as the open-loop plant.