# Dictionary:Comb

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,