STK 3D Electronically Steerable Phased Array Antenna Plugin

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STK 3D Electronically Steerable Phased Array
Antenna Plugin

• Trey Spetch, Jerry Odhner, and Kristen Jones

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What is a 3D Steerable Phased Array Antenna?

• Flat Panel Array of Elements
• Beam Electronically Steered by Varying Phase
  Across Elements
• Steerable in Both Azimuth and Elevation

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Applications of Electronically Steerable Flat
Panel Arrays

• Over the Horizon Radar
• Missile Searching and Tracking (Patriot Missile)
• Ship-Borne Radar
• Aircraft Antennas
• Must be conformal with aircraft
• No dishes allowed
• Large apertures achievable

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STK Static Antenna Patterns Not Suitable to Model
Phased Array Beam

• 90 Degree Elevation Beams 45 Degree Elevation
  Beams
• 1 GHz, 1m Aperture 1 GHz, 1m Aperture
• Array Antenna Dish Antenna
  Array Antenna Dish Antenna

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Antenna Notional Model
m 4
Crossed-Dipole Element
n 3
l/2
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Dihedral Angles to Boresight and ToObject

• Dihedral Angles for Boresight (f, q) and ToObject
  (a, b)

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Plugin Model
Coord Xform
ToObjectAz
b
ToObjectEl
a
G(m, n, l, q, f, a, b)
m, n, l
GainToObject
BoresightHoriz
q
BoresightVert
f
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Beam Steered to Invisible Vehicle
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Creating and Attaching Plugin Scripts
There are several kinds of plugins (constraints,
transmitter and receiver models, custom antenna
gain, etc) For a custom antenna gain plugin,
select the plugin file on the receiver properties
panel under Antenna Details
Languages Matlab, Perl, and VBScript. The
examples scripts that AGI provides are a good
place to start. You can then add any additional
input variables as needed and write functions to
do custom calculations.
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Plugin Code

• AntennaGainPlugin.vbs.doc

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Directivity Visualization Using STK Coverage
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Effect of Changing Array Dimensions

• Increasing the number of elements along one axis
  of the antenna decreases the beamwidth in that
  direction

5 x 5 Array, 1 GHz
5 x 10 Array, 1 GHz
10 x 10 Array, 1 GHz
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Effects of Wavelength

• For a given panel aperture size, the beamwidth
  decreases with wavelength

1 meter array (2x2), 500 MHz
1 meter array (7x7), 1 GHz
1 meter array (33x33), 5 GHz
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Conclusion

• STK Plugins allow dynamic beam shaping for
  antennas based on custom equations
• Any geometric variable or scalar value can be
  input to the plugin
• Allows extremely accurate modeling of link
  margins for phased arrays and other custom
  antennas

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Questions?