Nonrecursive comb structure with a very small passband droop and increased attenuation

This paper presents a novel nonrecursive comb structure with a very small pass band droop, where the decimation factor is power of two. The simple multiplierless compensator which works at low rate compensates for the passband droop. The compensation filter remains the same for all values of the decimation factors and the number of the cascaded comb filters K. Last p stages of the nonrecursive structure have six cascaded filters for all values of M and K. The first folding band has an improved attenuation. The other folding bands are either improved or equal to those of the original comb, depending on the value of p. The method is illustrated with examples and the comparison with one recently proposed method, is also provided.