NEW MATRIX-METHOD FOR MULTIPOINT PADE-APPROXIMATION OF TRANSFER-FUNCTIONS

A new way of formulating a multipoint Pade approximant of a linear sys tem transfer function is given. It is seen to be very flexible and com putationally efficient. The expansion points can be a mixture of real, complex, purely imaginary and multiple points with no complex arithme tic required. The underlying idea of the method is to convert the rati onal approximation problem into one of polynomial approximation. This results in simple matrix multiplications and the solution of a set of linear equations to derive the reduced model. Examples are given to de monstrate the application of the technique.