Design of Wideband Multiplierless Compensators for Sharpened CIC Filters.

We present here a new design of wideband compensators for sharpened cascaded-integrator-comb (CIC) filters. Two different magnitude responses of the compensator are considered. In the first design, magnitude response is a product of sinusoidal functions, while in the second design, it is a sum of sinusoidal functions. In both approaches, the design parameters are magnitudes of sinusoidal functions. The design parameters are determined by particle swarm optimization (PSO) in Matlab. Next, the optimum parameters are expressed in signed-power-of-two (SPT) forms. Both approaches are combined, resulting in the number of adders varying from seven to fifteen, while the corresponding maximum passband deviations change from 0.1238 dB to 0.0354 dB. The principal advantage of the presented compensator is the flexible choice of the desired number of compensator adders or the maximum value of the passband deviation.