Using Cascaded Non-Identical CIC Sections to Improve Insertion Loss

Abstract

A novel class of cascaded-integrator-comb (CIC) filter functions, which preserve the CIC filter simplicity avoiding the multipliers, is proposed in this paper. The proposed class is designed using several cascaded non-identical CIC sections. The paper provides its non-recursive and recursive forms, as well as frequency response. Compared with classical CIC finite impulse response (FIR) filters designed novel class shows excellent performances in term of insertion loss in stopband and selectivity. To verify the behavior of the proposed novel class of CIC FIR filter functions, several illustrative examples are provided. Also, comparisons of the novel filter class with existing classical CIC structures and some recent improvements given in the literature are provided. For the same level of a constant group delay of 31.5 s, a classical CIC filter function has insertion loss of 115.176 dB, and proposed novel filter function has 136.757 dB. It has achieved significant improvement of 21.581 dB or approximately about 20%.