Using the Goertzel algorithm as a filter

The Goertzel algorithm is fairly known algorithm in tone detection systems. This effective realization of a partial Fourier transform is able to evaluate selected spectral bin by a very simple algorithm. Additionally, the Goertzel algorithm can be used as a digital filter. The paper introduces derivation of the frequency characteristics of the Goertzel filter. Finally, the novel filter structure has been proved to eliminate a decimation property of the filter.