Novel two-stage comb decimator with improved frequency characteristic

This paper presents a novel low-power two-stage comb-based decimator in which the passband droop is decreased and the attenuation in all odd folding bands are increased. This is achieved by using simple corrector filter and the sharpening technique in the second stage. The only design parameter is the number of the cascaded comb filters K in the first stage. However, the second stage remains the same for all values of the parameter K. The proposed method is compared with the similar methods in the open literature. FPGA implementation proves that the proposed structure has improved characteristics at the cost of an increase of 33.3% in power consumption, compared with the comb.