Efficient comb-rotated sinc (RS) decimator with sharpened magnitude response

This paper presents a comb-rotated sine (RS) decimator with a sharpened magnitude response. The decimator is composed of two main sections. The first section is a cascaded comb decimator, while the second section is a cascade of a sharpened comb and a rotated sine (RS) decimator. Using the polyphase decomposition, the subfilters of the first section can be operated at lower rate, which depends on the down-sampling factor of the first section. Additionally, as the RS filter is in the second section, both multipliers of the RS filter work at the lower rate. The magnitude response of the proposed filter is improved by using the sharpened technique in the second section.