450
Practical MATLAB
® Applications for Engineers
d. The bandwidth of f 1 (t) and f 2 (t)
e. The bandwidth of [f 1 (t) + f 2 (t)]
P.4.9 Evaluate the following FTs by hand, using Table 4.1:
a. u(t)
b. 3 + 2u(t)
c. δ(t)
d. δ(t − 2)
e. 3δ(t − 4) + 6δ(t + 5)
f. cos(15t)
g. sin(2t)
h. cos(15t) sin(2t)
P.4.10 Repeat P.4.9 by using the MATLAB symbolic toolbox.
P.4.11 Using Table 4.1, determine by hand the following IFTs:
a. (Sin(w/ 2))/(w/ 2)
b. δ(w)
c. cos(3w)
d. 2/(jw + 2)
e. 3/(jw + 2)
2
f. −1/w
2
P.4.12 Repeat P.4.11 by using the MATLAB symbolic toolbox.
P.4.13 Obtain using MATLAB expressions and plots (magnitude and phase) of
a. F 1 (w) =
jw
______
2 + w
2
b. F 2 (w) =
1
_______________
(1 + jw)(2 − jw)
P.4.14 Determine f 1 (t) and f 2 (t) for the following frequency functions:
a. F 1 (w) = j/(2 − w + jw)
b. F 2 (w) =
1
_______________
(1 + w
2 )(2 − jw)
P.4.15 Let
f t
te u t
F w
jw
t
( )
( )
( )
(
)
ϭ
ϭ
ϩ
Ϫ2
2
1
2
↔
Obtain plots of
a. f(t) versus t
b. mag[F(w)] versus w
c. phase[F(w)] versus w
d. [power of f(t)] versus w
P.4.16 Given the system shown in Figure 4.91, use MATLAB to obtain the following
plots:
a. x(t) versus t
b. X(w) versus w
c. Y(w) versus w
d. y(t) versus t
CRC_47760_CH004.indd 450
CRC_47760_CH004.indd 450
7/28/2008 12:26:24 PM
7/28/2008 12:26:24 PM