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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

n = 3

/2

Crossed-Dipole Element

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Dihedral Angles to Boresight and ToObject

• Dihedral Angles for Boresight and ToObject (

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Plugin Model

ToObjectAzToObjectAz

ToObjectElToObjectEl

m, n, m, n,

CoordXform

G(m, n, )

BoresightVertBoresightVert

BoresightHorizBoresightHoriz

GainToObjectGainToObject

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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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5 x 5 Array, 1 GHz

Effect of Changing Array Dimensions

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

5 x 10 Array, 1 GHz

10 x 10 Array, 1 GHz

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Effects of WavelengthFor 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?