IEEE Transactions on Automatic Control, Vol.47, No.5, 837-841, 2002
Frequency-domain synthesis of a filter using Viete root functions
This note proposes a noniterative method to fit a rational transfer function to a specified frequency response. A method using a smoothing of width-modulated pulses of the phase asymptotic-diagram is modified to provide an exact algebraic method. This is then used to synthesize a robust controller and a nonrational transfer function with a fractional differentiation order.
Keywords:approximation;filter synthesis;fractional differentiation;frequency-domain method;model reduction;system identification;Viete root functions