Mixer controlled variable passband finite impulse response filter

摘要

A mixer controlled, variable passband, finite impulse response filter has a plurality of individual filter function blocks which are cascaded. The filter function of each of the individual filter function blocks is represented by a fixed filter function block having a linear phase response. The junctions between successive filter function blocks form signal taps. The signal from each signal tap is delayed by a compensating delay device so that the signals from each of the plurality of signal taps have the same phase function. Signals from selected signal taps are then combined in a predetermined manner to achieve a desired filter transfer function.