1
School of Electrical and Computer Engineering, Cornell University
ECE 303: Electromagnetic Fields and Waves
Fall 2005
Homework 10
Due on Nov. 04, 2005 by 5:00 PM
Reading Assignments:
i) Review the lecture notes.
ii) Review sections 6.5, 7.1, 7.2, paperback book
Electromagnetic Waves
.
NOTE:
To save time, you can print out as many copies as you like of the empty sketch templates at the
end of the problem set and attach these to you answers to problems 10.1 through 10.5.
Problem 10.1: (Turn-on transient)
Consider the following transmission line circuit:
The source voltage is a step function given by:
() ()
t
u
t
V
s
4
=
a) Plot the voltages
()
t
z
V
,
+
,
()
t
z
V
,
−
, and
( )
t
z
V
,
on the transmission line at time
v
t
2
l
=
.
b) Plot the voltages
()
t
z
V
,
+
,
()
t
z
V
,
−
, and
( )
t
z
V
,
on the transmission line at time
v
t
2
3
l
=
.
c) Plot the voltages
()
t
z
V
,
+
,
()
t
z
V
,
−
, and
( )
t
z
V
,
on the transmission line at time
v
t
2
5
l
=
.
d) Plot the voltages
()
t
z
V
,
+
,
()
t
z
V
,
−
, and
( )
t
z
V
,
on the transmission line at time
∞
=
t
.
Problem 10.2: (Switching transient – load end)
Consider the following transmission line circuit:
Z
o
= 5
Ω
R
s
15
Ω
15
Ω
V
s
(
t
)
R
L
Z
o
= 50
Ω
R
s
50/3
Ω
50/3
Ω
V
s
(
t
)
R
L
z
= -
ℓ
z
= 0
z
= -
ℓ
z
= 0