Active RC filters were first applied in the late 1950s. Since then, there has been a rapid development in both theoretical research and practical realization methods, as witnessed by the appearance of some 3,000 publications on active RC filters. This abundance of literature has, however, caused a great deal of confusion for non-specialist engineers. In order to solve a problem of filter design, a prolonged study is usually needed in order to make the correct choice between a wide variety of filter structures. Furthermore, most publications are intended to solve detailed problems for experts in the field, with little useful contribution for practising electrical engineers.
Now, with the aid of this book, the designer can find the structure and circuit elements of a specified active RC filter with relatively few calculations. Moreover, the filter thus designed will have transfer characteristics within the specified tolerances, and will comprise the least expensive (i.e. highest tolerance) components.