Transcript Field Coupling into the A380 Aircraft Dietmar Leugner, H.-D. Brüns [email protected] [email protected] Introduction The field equivalence principle Special consideration for slots Demonstration by means of a small.

Field Coupling into the A380 Aircraft
Dietmar Leugner, H.-D. Brüns
[email protected]
[email protected]
Introduction
The field equivalence principle
Special consideration for slots
Demonstration by means of a small example
Numerical model of the A380 aircraft with back doors
Fully discretized model, EFIE problem
Coupling-in results based on the application of equivalent currents of
magnetic type
Conclusion
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Introduction
Fully discretized MoM
model
10219 unkowns
Typical element
dimensions from
2 cm² to 2500 cm²
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Introduction
Loop antenna, HF range
Numerically critical because
of very low radiation
resistance
Stable solution only with
inserted wire grid
Validation: power budget
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Typcal results for the HF range (A380)
Loop antenna input impedance
Radiation diagram at
30 MHz
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Huygens principle in electromagnetics
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Transition slot / conducting part
(problem of end charges)
Possible solution:
overlap
and inclusion of
into the system matrix
as impressed current
(to be done)
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Illuminated sphere at 300 MHz
Geometry
Field vectors in log. scale
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Coupled-in E field
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Discretization of back door (1)
Door: 0.9m x 1.9m
Slot width: 1 cm
Surface currents at 30 MHz
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Discretization of back door (2)
Details of slot
discretization
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Failure of classical EFIE (1MHz, 0°)
Cross section of empty aircraft
Closed Model
Model with door
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E field at 1 MHz generated by magnetic currents (phase 0°)
Cross section of empty aircraft
Vectors are plotted in
log. scale
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E field caused by magnetic slot currents
1 MHz
30 MHz
Maximum magnitude of E in cross section of empty aircraft
Aircraft structure completely neglected
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Conclusion
Small slots in large conducting bodies cannot be treated
sufficiently by a MoM-EFIE approach
Equivalent currents in slots and apertures acting as excitation
sources provide an alternative
Special treatment at the intersecting line of Huygens surfaces and
MoM surfaces is necessary
Application of purely magnetic slot currents give a first order
solution
The method works only if completely decoupled spaces are
considered
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