1 PHY 712 Electrodynamics 101050 AM MWF Olin 107 Plan for Lecture 19 Start reading Chap 8 in Jackson Examples of waveguides TEM TE TM modes Resonant cavities 03172013 PHY 712 Spring 2014 Lecture 19 ID: 604499
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PHY 712 Spring 2014 -- Lecture 19
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PHY 712 Electrodynamics10-10:50 AM MWF Olin 107Plan for Lecture 19:Start reading Chap. 8 in Jackson.Examples of waveguidesTEM, TE, TM modesResonant cavities
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PHY 712 Spring 2014 -- Lecture 19
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Reminder:Topic choices for “computational project” – suggestions available upon request-- due Monday March 24th?
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PHY 712 Spring 2014 -- Lecture 19
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Fields near the surface on an ideal conductor
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Fields near the surface on an ideal conductor -- continued
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PHY 712 Spring 2014 -- Lecture 19
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Fields near the surface on an ideal conductor -- continued
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PHY 712 Spring 2014 -- Lecture 19
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Fields near the surface on an ideal conductor -- continued
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PHY 712 Spring 2014 -- Lecture 19
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Boundary values for ideal conductorAt the boundary of an ideal conductor, the E and H fields decay in the direction normal to the interface.
H
0
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Waveguide terminologyTEM: transverse electric and magnetic (both E and H fields are perpendicular to wave propagation direction)TM: transverse magnetic (H field is perpendicular to wave propagation direction)TE: transverse electric (E field is perpendicular to wave propagation direction)03/17/2013Slide10
PHY 712 Spring 2014 -- Lecture 19
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Wave guidesCoaxial cable
TEM modes
Top view:
a
b
m e
z
(following problem 8.2 in Jackson’s text)
Inside medium,
m e
assumed to be real
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Electromagnetic waves in a coaxial cable -- continued
Top view:
a
b
m e
r
f
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PHY 712 Spring 2014 -- Lecture 19
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Electromagnetic waves in a coaxial cable -- continued
Top view:
a
b
m e
r
f
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Analysis of rectangular waveguideBoundary conditions at surface of waveguide: Etangential
=0,
B
normal
=0
z
x
y
Cross section view
b
a
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Analysis of rectangular waveguide
z
x
y
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PHY 712 Spring 2014 -- Lecture 19
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Maxwell’s equations within the pipe:
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PHY 712 Spring 2014 -- Lecture 19
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Solution of Maxwell’s equations within the pipe:
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TE modes for retangular wave guide continued:
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PHY 712 Spring 2014 -- Lecture 19
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Solution for m=n=1
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PHY 712 Spring 2014 -- Lecture 19
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Solution for m=n=1
k
w
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PHY 712 Spring 2014 -- Lecture 19
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Resonant cavity
z
x
y
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PHY 712 Spring 2014 -- Lecture 19
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03/17/2013Resonant cavity
z
x
y