Digital-filter 2nd-order element with low quantising noise for poles and zeros at low frequencies

A 2nd-order recursive digital-filter element is proposed that gives an appreciable reduction in signal quantising noise and coefficient sensitivity compared with the direct or canonic forms of filter element when the poles or the zeros are near the point Z= 1+0j. This is a modificalion to a previously published 2nd-order element that only gives an improvement when the poles are near the point Z=1+0j.