How to solve the sharpening problem for signal edges after passing through multi-stages filter

[Emad_NRIAG]

I'm trying to design multi-stages multi-rates decimation filter. I'm using the built-in labview vi (DFD NStage MRate Filter Design VI). To test the system, a sine wave is sampled with 30 KHz, then, decimated to 100S/s using three stages filter. However, the edges of the output signal are not smooth (sharpen). Kindly, give me a suggestion to solve this problem.

Kindly, download the attached files for more information.   

[altenbach]

Your output has less than 10 samples per period. this is insufficient for a "smooth" output, whatever that means.