This paper presents a comb-based nonrecursive decimation structure with improved magnitude characteristics, where the decimation factor M is a power of two. A rotated cosine filter is introduced to increase the attenuation in the folding bands. Additionally, the passband droop is decreased by using a simple multiplierless compensation filter which works at low rate. The multiplierless rotated term is also introduced. The method is illustrated with examples and the comparisons with other methods are provided.