A rectangular pulse transforms into a sinc-shaped spectrum.

Evidence

The function sin( ) x x/ appears so often that it has its own name: sinc(x). So we can say the Fourier transform of the rectangular pulse as described in Equation A1.11, is: Note that in this case F() turns out to be real; that is, it has no imaginary part. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2763

Categorization

• XREF: Connects to windowing and transient smearing in digital audio.