Wiley signals and systems e book TLFe BO 308

11.4. Exerrises

293

a) Draw A(j.-i)9-0 a ( t ) and a suitable example for X ( p ) in tlsc same slietch.
b) Comparc the amplification of the aperture fL1nction at the frrqurirc-y zero
and at the band limits of 1ht3 signal. By 1 . t ~ rnaiiy
)~
dB is it, less at the I m d
limits?
c ) DctPrmine z so that the aperture functioii riialirs il suitahle prcliniiriary anti-

aliasing filter if sarripling is carried out at

.fa

= 10 kHL.

Exercise 11.24

The effect of triple projection 011 the flirlterivlg of cinematic films (see Examplc 11.2)
will br im-estigat,ed. The interpolation filtw takes the form of a mechanical sliu
with t he sketched

Express h ( t ) using recl-hurtions and (5-impnlses, as clescribed in (11 5 3 ) . Then
H ( p ) and skctch J H ( j u ) l€01 T =
In particular, try to deiitify
the zeros of H ( p ) .

&.