A synthesis of pipelineable wave digital filters by scattering matrix factorization

This paper proposes a synthesis of low‐sensitivity digital filters which are pipelineable and have simple structures. Their sensitivity characteristics are similar to those of wave digital filters. The synthesis of these filters is attained by factorizing paraunitary scattering matrices derived from given z‐domain transfer functions without referring to analog filters. The synthesized structures are the T‐cascade connection of fundamental sections which are constructed by using series and parallel sections of wave digital filters. The proposed synthesis method can realize any given IIR transfer function, while previous methods which synthesize T‐cascaded structures can realize only the amplitude response of any given transfer function. In addition, the method can realize the transfer functions of which the order of their denominator is higher than that of their numerator including FIR transfer functions.