ECE 1100 Introduction to Electrical and Computer Engineering

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ECE 6340 Intermediate EM Waves
Fall 2005
Prof. David R. Jackson ECE Dept.
Notes 28
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Dipole on Ocean
Goal Find Ey (r0)
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Dipole on Ocean (cont.)
Geometry for reciprocity
The ocean is the body.
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Dipole on Ocean (cont.)
The reaction lt a, b gt is the field we are trying
to calculate.
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Dipole on Ocean (cont.)
The reaction lt b, a gt is the field at the surface
of the ocean due to the testing dipole.
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Dipole on Ocean (cont.)
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Dipole on Ocean (cont.)
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Dipole on Ocean (cont.)
To find the incident field
where
Hence
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Dipole on Ocean (cont.)
Therefore, we have
Hence, from reciprocity,
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Dipole on Ocean (cont.)
Summary
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Arbitrary Angle ?
Now consider an arbitrary observation angle ?
(observation point stays in yz plane)
y
Hence
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Arbitrary Angle ? (cont.)
From plane-wave theory we have
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Arbitrary Angle ? (cont.)
Summary
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Arbitrary Angle ? (cont.)
Summary (cont.)
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Arbitrary Angles ? and ?
Most general case (arbitrary ? and ?)
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Arbitrary Angles ? and ? (cont.)
Hence
Note the reflection coefficient depends only on
? and not ?.
A similar calculation can be done to determine
the ? polarization
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Arbitrary Angle ? (cont.)
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Arbitrary Surface Current
z
?
Jsy ( x, y )
y
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Arbitrary Surface Current (cont.)
Similarly,