
-10 -
-20 -
n~
-o -30 -
E
-40 -
C
o
.,.,
-50 -
C
m
-60 -
-70 -
-80
I I ! I I
1 2 3 4 5
I 1 I I I I I I
6 7 8 9 10 11 12 13
5.75 13.5
0.25 0.5
0.5n n
Frequency,
MHz
Frequency,
fraction off s
Frequency,
w, tad. s-1
+0.050
~ 1
E +0.025
0
_c -0.025
-0.050~
Figure 16.25 Half-band filter. This graph shows the frequency response of a practical filter whose
corner is at one-quarter its sampling frequency of 27 MHz. The graph is linear in the abscissa
(frequency) and logarithmic in the ordinate (response). The top portion shows that the
passband
has an overall gain of unity and a uniformity ...