An Overview on Hybrid Integrator-Gain Systems with applications to Wafer Scanners

Hybrid integrator-gain systems (HIGS) are non- linear control elements that switch between simple integrator dynamics and gain characteristics. Switching is done in a way that guarantees sign-equivalence of the integrator’s input-output pair, thereby enabling phase advantages over linear integrators as seen through describing function analysis. This paper provides an overview of the state of the art in HIGS controlled systems analysis and design with applications to wafer scanners.