The ability to export the filter coefficients of polyphase filters directly to your MATLAB workspace is not available in the Filter Design & Analysis tool (FDATool).
To work around this issue, export the polyphase (multirate) filter from FDATool to your MATLAB workspace as a filter object. Then use the function POLYPHASE to determine the coefficients for the subfilters. POLYPHASE returns the polyphase matrix of the multirate filter object.
Once you have designed your filter in the Filter Design & Analysis Tool, export it by selecting "File->Export" from the FDATool menu bar. In the resulting Export dialog, select "Object" from the "Export As" list and note the variable name, or enter a variable name.
After the object is in your MATLAB workspace, access the individual filter coefficients by issuing the following command:
In this example, hm is the multirate filter object exported from FDATool and each row of p, the polyphase matrix, contains the filter coefficients for one subfilter phase.
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