On the Sensitivity of Canonically Extended RC‐Active MultiloopFilters

A class of multiloop active filters based on a double RC ladder of simple recurrent structure, constrained by a single, positive gain, voltage-controlled voltage source has received recent attention in the literature. Some design considerations are discussed in this paper and sensitivity results are presented which permit comparisons to be made between filter realizations with different types of capacitance spread constraints. It is shown that the common practice of constraining all capacitors to be equal leads to high sensitivity and that, by relaxing this zero-spread requirement, much more favourable sensitivity results can be obtained.