Post on 30-Dec-2015
description
Electromagnetic Wave Propagation
Maxwells equations
Plane Electromagnetic Wave4.1
1 Maxwells equations
Maxwells equations
0a) 68
86
XCCb)
Fourier2 (9)(10)
(11)Maxwells equations a) Maxwells equationscost
Maxwells equations b) Helmholtz)
0Helmholtz(16)(17)Helmholtz
Maxwells equations
Maxwells equationsHelmholtz3
l f
x>>l A A BC
A
2
Helmholtz
b) 2
c)
d)
a) 4
b)
0
:
4.2 Reflection and Refraction of Monochromatic Plane Electromagnetic Wave at Interface of Medium
Maxwell
2: 1:
1 Law of Reflection and Refraction ( i.e. Phase Relation)
Maxwells equations
a) Faraday)
L1=L2=LS1=S2=S
b)
x-y z = 0
Fourier
z=0 z=0 z=0
xyt
= c) b) a)
n2121 d)
2 Fresnels Formulai.e. Amplitude Relation
a)
y12
b)
, y z=0
4000 8000
1
+ -
+-
2 3
Brewsters angle 4
>1
5 T R
(Total Reflection Critical Angle)
3 Total Reflection) 1 >
z x 22
2
()
2 Sz x
4.3 Electromagnetic Wave Propagation in Conduction Medium
Gauss 1
00 t=0
Maxwell equs = 02
(a) :
(b):
(c)
=0
Z
3
a) , R Joule, ,
,Jouleb)
c)
19894 ( )
d)
e)
4 f )
HI EV
R
5
:
4.4 Electromagnetic Wave Propagation in Wave Guide
TEM TEM
(wave guide)TEM 1
abxyz abz :
0
, (
z
u ( x , y )
X(x) Y(y)
ABCD z
a) y = 0Ex= 0
b) y=bEx= 0 . D = 0
c) x = 0
d) x=a
f ) y=0 e) x=0
g) x=a, y=b 5
, :,2TEWTMW ExEyEzHxHyHz m , n)Ez=0
TEW TEW TMWTEWTMWm,nTEmnTMmn
TMW3 a) TEMW
b)
c) mnmnm,nTMTMmnTETEmna,bTEmnTMmnm,n
z zTEmnTMmn (Critical state) (Cut-off frequency)
(Cut-off wavelength)
d) TEmnm=1,2,3,n=0,1,2,m=0,1,2,n=1,2,3,TMmnm=1,2,3,n=1,2,3,TE10TE01TM11
TE10 a>b e)
u
uuga,bm,n uCugC
3 Resonant cavity
xyz u ( x , yz )
1.02MeV,