Passband and stopband CIC improvement based on efficient IIR filter structure

This paper introduces the efficient second order IIR filter which considerably improves the passband as well as the stopband of the Cascaded-Integrator-Comb (CIC) filter. Using the polyphase decomposition the filter can be moved to a lower rate, which is D times less than the high input rate, where D is the decimation factor. The phase of the filter is approximately linear in the passband. The design parameters are the number of cascaded CIC filter K, the decimator factor D, the passband frequency ω_p and a weighted parameter α.