Laguerre-based bandlimited reduced-order modeling

A new bandlimited Laguerre basis for application to reduced-order modeling (ROM) is proposed. It is derived from the original Laguerre basis by means of a judiciously chosen rational frequency transformation, shown to be orthonormal over a narrow-band frequency interval. By means of projecting the original transfer function onto this bandlimited Laguerre basis, we obtain a new ROM technique, which does not belong to the class of Krylov methods, but to the rather more general family of projection techniques. Pertinent features of the new method are the reduction in computational effort, the fact that a more efficient ROM approach is obtained by focusing on a frequency band at a time and the better extrapolation power of the new method, as compared to previous methods. The feasibility of the new method is illustrated by means of three examples.