FILSYN—A general purpose filter synthesis program

A very general computer program is described that can be used for the synthesis of passive LC, active RC, and (infinite impulse response) digital filters. Although it operates in both batch and interactive modes, this discussion deals exclusively with the interactive mode, which is somewhat more general and very easy to use. Apart from offering superior accuracy and flexibility, this program offers many firsts, including the passive realization of complex quadruplets of transmission zeros, the simultaneous realization of two transmission zero pairs, the active RC leapfrog realization, and many others.