Modified nonrecursive comb decimation structure

This paper presents the nonrecursive comb decimation structure for the decimation factors which are the power of five. As a difference to CIC (Cascade-Integrator-Comb) structure which is area efficient, a nonrecursive structure is a power efficient. However, this structure has a low attenuation in the folding bands (bands around the zeros of comb filter), which can deteriorate the decimated signal. We proposed a modified structure in which a simple multiplierless filter is inserted in the last stage. The proposed method is based on exploiting the properties of the system function of the convolution of a comb filter with itself.