Low-sensitivity digital filters based on zero extraction

A method is proposed for synthetizing digital filters derived from the LBR two-pair extraction technique. The method forces the LBR two-pairs to have their transmission zeros coincident with those of the filter. The basic two-pair having transmission zeros on the unit circle is considered in detail with regard both to the realization problem and to the simplification of the synthesis procedure. In particular, explicit formulas are proposed for directly determining the representation of this two-pair. A simulation example illustrates the sensitivity performance of the resulting schemes.