CIC Decimator Droop Compensation with Minimum-Order CIC Compensator

This code designs a minimum-order CIC compensator to compensate for the droop in the passband of a CIC decimator.

First, it defines the input sampling frequency (Fs = 45.5e6), the frequency band of interest (Fpass = 0.5e6), and the decimation factor (D = 14).

Then, a CIC filter is designed using the fdesign.decimator function with parameters specifying the decimation factor, filter type, and desired passband characteristics. The design function is then used to generate the filter's transfer function.

Next, a CIC compensator filter is designed using the fdesign.ciccomp function. This function takes as input the differential delay and number of sections of the CIC filter, along with the desired passband characteristics and other parameters. Again, the design function is used to generate the transfer function.

Finally, the fcfwrite function saves the structures of the CIC and CIC compensator filters to a '.fcf' file for further analysis. The fvtool function is used to plot the magnitude and phase responses of the CIC, CIC compensator, and the overall response for visual inspection.

The code provides a clear and concise implementation for designing a CIC compensator to address the passband droop issue in CIC decimation. It leverages MATLAB's signal processing toolbox functions for efficient filter design and analysis.