A common requirement in many signal processing applications is a
bandpass filter network to precondition an input signal to a
desired range of frequencies. Traditionally, this circuit has been
implemented using basic analog building blocks (e.g. operational
amplifiers) in conjunction with fixed resistors and capacitors to
set the center frequency (f 0) of the bandpass filter.

The figure below shows a programmable infinite gain multiple
feedback (IGMF) bandpass filter. These filters are characterized by
a fixed, five component configuration.