An infinite sequence of impulses occurring at time intervals :
called the sampling function because multiplying a function by a comb gives the sample values at the comb interval, and the replicating function because convolution with a waveform reproduces the waveform at the position of each comb spike. Also called a shah, named for the Cyrillic symbol ш. The Fourier transform of a comb is also a comb:
where frequency f=1/t if t is time and indicates a Fourier transform operation. See Figures C-8 and F-19.
If the impulses are spaced T apart,