Efficient multistage modified comb structure with the improved magnitude response

This paper presents a new multistage decimation comb filter structure with an improved magnitude response. Each section is a cascade of the simple comb filters. The first section is realized in a nonrecursive form. By using the polyphase decomposition the filters of the first section can be moved to the lower rate. The sharpening technique is used to improve the magnitude characteristic of the structure. The proposed decimation filter is multiplier-free and does not have any filtering at the high input rate.