
Impulse
(point sampling)
1
t
Constant
I I
0 2n
•••
sinc
o
Boxcar
i i
0 2n
~ sinc2
T T q'-
0 1
~~ Triangle
i
0 2n
~
~, Gaussian
I I
0 1
'~ Gaussian
I I
0 2n
Triangle ("tent,"
linear interpolation)
1
0 1 t
~_ sinc2
i q-- T
0 2n
Boxcar
(nearest neighbor)
I
o 1 t
•
///~'~ sinc
0 ~co
i .... i
Constant
I I
0 1 t
Impulse
I I .....
0 2n oJ
Figure 16.9
Fourier transform pairs
for several functions are shown in these graphs. In the left
column is a set of waveforms in the time domain" beside each waveform is its frequency spectrum.
CHAPTER 16 FILTERING AND SAMPLING 151