.FTD File

The ftd file extension is related to FFT Designer and used for its project file. 

FFT Designer allows users to quickly simulate and explore the performance of a Fast Fourier Transform combined with any standard window function such as Hamming, Flat-Top, Kaiser, Blackman-Harris and others.

How to open:

Use FFT Designer to open *.ftd files.

How to convert:

FFT Designer may be able to export *.ftd files to other formats.