Frequency domain performance analysis of Selva's interpolator

Recently, Selva et al. presented a novel implementation form for interpolation filter as an alternative approach to polynomial-based interpolation filters and Farrow structure. The Selva's interpolator has been used for design and implementation of fractional delay filters. The filter has been designed using an approximate prolate window. However, the frequency response of the filter has not been analyzed. In this contribution, we analyze the frequency response of Selva's interpolator and we compare it to the Farrow structure. Finally, we show that Selva's interpolator can have very selective frequency domain performance, and thus it can be effectively used in some DSP applications.