Performance analysis of cascaded integrator-comb filter in modulator

For pre-compensating the passband droop of cascaded integrator-comb (CIC) filter, a novel method and its implementation algorithm are proposed, which uses the pulse shaping filter (PSF) while brings no additional hardware complexity. Then, an application example is given of a multi-rate quadrature modulator with a compensated CIC filter, and the frequency response of the whole system is analyzed. Moreover, the quality of the modulated signals is evaluated by simulation. The simulation results verify the validity of the proposed compensation method and its practicability of the compensated CIC filter.