Design of cascaded allpass structures with magnitude and delay constraints using simulated annealing and quasi-Newton methods

For high sampling rate applications it is useful if the digital filter structure is efficient in the sense of a minimum number of arithmetic operations for a given order. In addition, requirements for satisfying the stringent magnitude and delay specifications lead to the choice of non-minimum phase transfer functions. To this end, a filter structure is considered which is made up from all-pass sections. Two design approaches are examined using classical optimization and simulated annealing. Design examples are provided which illustrate the efficacy of these techniques