0
d Q
S
E s
D. K. Cheng, Field and Wave Electromagnetics, 2nd ed., Addison-Wesley, 1989.
0
2
rLE r l L
(V/m) 2 0 r
l
r
a E
b R
b R
for 0 for 0
0
ds d
E R R
R s a
a
E ,
0 R b
i
i R S
S E ds E ds
Q V dv 0 V dv
R R
0 0
3 a E
4 R 2
E R
3
0 3
4 R
R > b
Q 0 3
3 4 b
2 0
3 0
3 R
b
R
a E
D. K. Cheng, Field and Wave Electromagnetics, 2nd ed., Addison-Wesley, 1989.
D. K. Cheng, Field and Wave Electromagnetics, 2nd ed., Addison-Wesley, 1989.
D. K. Cheng, Field and Wave Electromagnetics, 2nd ed., Addison-Wesley, 1989.
) V or J/C
2 (
1
P
P d
q
W E l
V
E
2
1 2
1
) (
)
P (
P l
P
P E d l V a dl
1 2
2
1
V V
P dV
P
D. K. Cheng, Field and Wave Electromagnetics, 2nd ed., Addison-Wesley, 1989.
1 2
0 21
1 1
4
1
2 R R
V q V
V P P
) V 4 0 R (
V q
dR
R
V R a R q a R
2
4 0
n
) 4 (
1
0 1
R V
R
n
k k
q k
V
R p
R
R
V q 1 1
4 0
d << R
2 / 1 2
2 ) cos
( 2
1
d Rd
R R
cos
1 2 1
R d
R 1 / 2
2
2 ) cos
( 2
1
d Rd
R R
cos
1 2 1
R d
R 4 0 2
cos R V qd
( V )
4 0 R 2
V R
a p
V
E
V
R R
V
R
a 1 a
2 cos sin
4 0 3 a a
R
R p
D. K. Cheng, Field and Wave Electromagnetics, 2nd ed., Addison-Wesley, 1989.
R V q
4 0
d v
V R
V
0 4
1
s R d
V S
s
4 0
1
l R d
V L
l
0 4
1
0
w E d t
abcda
h
E l lim 0
•
•
•
0
E
0 E t 0
S E
d n
h S
E s lim 0
0
s S
0
E t
0
s E n
D. K. Cheng, Field and Wave Electromagnetics, 2nd ed., Addison-Wesley, 1989.
tot 0
Q
0
s E n
D. K. Cheng, Field and Wave Electromagnetics, 2nd ed., Addison-Wesley, 1989.
Q
R > R o
4 2
1 R
E
d R
S
E s
0
Q
2
4 0
1 R
E R Q
V R E R dR
1
1 R
Q 4 0
R i < R < R o
2 0
E R
R o
V R
V
1
2
R o
Q 4 0
R < R i
2
4 0
3 R
E R Q
V 3 E R 3 dR C Q R C
4 0
3 V 2
V
R i
R
o
i R
R R
V Q 1 1 1
4 0
3
D. K. Cheng, Field and Wave Electromagnetics, 2nd ed., Addison-Wesley, 1989.
