A Generic Destroyer Class Warship Electromagnetic Compatibility

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A Generic Destroyer Class Warship-Electromagnetic
Compatibility

• Guy Morris
• UniSA
• 27Sep05

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Acknowledgements

• DSTO
• Dr Pina DallArmi-Stoks
• Dr Andrew Walters
• Dr Chris Leat
• Mr Stuart Thomson
• UNISA
• Mr Jan Machotka

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AIM

• To develop a technique for identifying EMI\EMC
  issues on a maritime platform.
• GOALS
• Create a Geometrical Model for use in FEKO
  representing a generic destroyer class warship.
• Create a model of a generic phased array radar.
• Create a model of a generic Electronic Support
  (ES) antenna.
• Determine the Electromagnetic Interference caused
  by the coupling of the antennas onboard a generic
  destroyer class warship.

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Reciprocity Theorem for Antennas
Methods

• The system response is not changed when the
  source and observation points are interchanged
  (Microwave Engineering, Pozar)
• Friis power transmission equation (Microwave
  Engineering, Pozar)

• Uniform Theory of Diffraction
• Faster than Method of Moments, Finite Element
  Method, Fast Multipole Method
• Better suited to antennas located on large
  structures and antenna coupling
• Frequency independent

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EMI/EMC

• EMI - Electromagnetic Interference
• EMC - Electromagnetic Compatibility
• What it is.
• Why we dont want it.

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Generic Destroyer Class Warship
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Generic Destroyer Class Warship

• Wire Frame .dxf file contains 22,000 plates

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Generic Destroyer Class Warship
Modified version approximately 285
plates Polygonal plates for UTD
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Generic Destroyer Class Warship

• Generic Phased array Radar

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Phased Array Radar

• Over 4000 elements
• 3.7 metres in diameter

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Phased Array Radar

• Elements modelled on ?/2 dipoles
• Near Fields calculated ?/4 away from the plate

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Phased Array Radar

• Calculated Parameters
• Physical Aperture size 10.8 m²
• GainND41.5 dB

• Simulated Parameters
• Effective Aperture size 11.4 m²
• Gain41.5 dB

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ES Antenna

• Cavity Backed Spiral Antenna
• Right Hand Circular Polarisation (RHCP)
• 3dB beamwidth 60 degrees
• Gain Calculated at 10dB
• Radius calculated at 5cm

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Simulation Model
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Simulation Model
ES Antenna
Phased Array Radar
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Coupling Factor between Phased Array and ES
Antenna
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Coupling Factor of Phased Array in Free Space
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Approximately 1 million ray paths calculated
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Future Applications

• EMI/EMC issues with other sensors on the platform
• EMI/EMC considerations with other platforms in
  the area
• Incorporation of other sources on the platform

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• QUESTIONS?