DIRECTION FINDING PERFORMANCE OF ANTENNA ARRAYS ON COMPLEX PLATFORMS ...

146 Pages·2011·7.6 MB·English

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DIRECTIONFINDINGPERFORMANCEOFANTENNAARRAYSONCOMPLEX
PLATFORMSUSINGNUMERICALELECTROMAGNETICSIMULATIONTOOLS
ATHESISSUBMITTEDTO
THEGRADUATESCHOOLOFNATURALANDAPPLIEDSCIENCES
OF
MIDDLEEASTTECHNICALUNIVERSITY
BY
MUSTAFAONURO¨ZEC¸
INPARTIALFULFILLMENTOFTHEREQUIREMENTS
FOR
THEDEGREEOFMASTEROFSCIENCE
IN
ELECTRICALANDELECTRONICSENGINEERING
SEPTEMBER2011
Approvalofthethesis:
DIRECTIONFINDINGPERFORMANCEOFANTENNAARRAYSONCOMPLEX
PLATFORMSUSINGNUMERICALELECTROMAGNETICSIMULATIONTOOLS
submitted by MUSTAFA ONUR O¨ZEC¸ in partial fulfillment of the requirements for the
degreeof
Master of Science in Electrical and Electronics Engineering Department, Middle East
TechnicalUniversityby,
Prof. Dr. CananO¨zgen
Dean,GraduateSchoolofNaturalandAppliedSciences
Prof. Dr. ˙IsmetErkmen
HeadofDepartment,ElectricalandElectronicsEngineering
Prof. Dr. T.EnginTuncer
Supervisor,ElectricalandElectronicsEng. Dept.,METU
ExaminingCommitteeMembers:
Assoc. Prof. Dr. S¸ims¸ekDemir
ElectricalandElectronicsEng. Dept.,METU
Prof. Dr. T.EnginTuncer
ElectricalandElectronicsEng. Dept.,METU
Dr. ArzuTuncayKoc¸
ElectricalandElectronicsEng. Dept.,METU
Dr. FatihKamıs¸lı
ElectricalandElectronicsEng. Dept.,METU
Dr. SerkanKaraku¨tu¨k
M˙IKESInc.
Date:
Iherebydeclarethatallinformationinthisdocumenthasbeenobtainedandpresented
in accordance with academic rules and ethical conduct. I also declarethat, as required
bytheserulesandconduct,Ihavefullycitedandreferencedallmaterialandresultsthat
arenotoriginaltothiswork.
Name,LastName: MUSTAFAONURO¨ZEC¸
Signature :
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ABSTRACT
DIRECTIONFINDINGPERFORMANCEOFANTENNAARRAYSONCOMPLEX
PLATFORMSUSINGNUMERICALELECTROMAGNETICSIMULATIONTOOLS
O¨zec¸,MustafaOnur
M.Sc.,DepartmentofElectricalandElectronicsEngineering
Supervisor : Prof. Dr. T.EnginTuncer
September2011,124pages
An important step for the design of direction finding systems is the performance evaluation
usingnumericelectromagneticsimulationtools. Inthisthesis,amethodispresentedforboth
modeling and simulation in a numeric electromagnetic simulation tool FEKO. The method
relies on the data generated by FEKO. The data is then processed by correlative interferom-
eter algorithm. This process is implemented in a MATLAB environment. Different types of
antennaarraysincludingdipole,monopoleanddisconeantennasareused. Theantennaarrays
are mounted on a UAV and SUV in order to see the platform effects. The direction finding
performanceisevaluatedfordifferentscenarios. Itisshownthatthepresentedapproachisan
effectivetoolforunderstandingthedirectionfindingcharacteristicofantennaarrays.
Keywords: DirectionFinding, CorrelativeInterferometer, NumericalElectromagneticSimu-
lationTools,PlatformEffects
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O¨ Z
ANTEND˙IZ˙ILER˙IN˙INKARMAS¸IKPLATFORMLARDANU¨MER˙IK
ELEKTROMANYET˙IKS˙IMU¨LASYONYO¨NTEMLER˙IYLEYO¨NBULMA
PERFORMANSLARININ˙INCELENMES˙I
O¨zec¸,MustafaOnur
Yu¨ksekLisans,ElektrikveElektronikMu¨hendislig˘iBo¨lu¨mu¨
TezYo¨neticisi : Prof. Dr. T.EnginTuncer
Eylu¨l2011,124sayfa
Yo¨n Bulma sistemlerinin tasarımındaki o¨nemli adımlardan biri Nu¨merik Elektromanyetik
Simu¨lasyonarac¸larıylaYo¨nBulmaperformanslarınındeg˘erlendirilmesidir. Butezde,Nu¨merik
ElektromanyetikSimu¨lasyonaracıolanFEKOprogramıvasıtasıylamodellemevesimu¨lasyon
yo¨ntemi gelis¸tirilmis¸tir. Bu metod, FEKO programında olus¸turulan verilere dayanmaktadır.
FEKO’da elde edilen veriler Korelatif Enterferometre algoritması vasıtasıyla MATLAB or-
tamındaYo¨nBulmaperformansınıbelirlemekic¸inkullanılmaktadır.Buc¸alıs¸madadipol,monopol
ve du¨s¸ey konili anten dizileri kullanılmıs¸tır. Anten dizileri, platform etkilerini go¨zlemlemek
ic¸inUAVveSUVarac¸larınamonteedilmis¸tir. Yo¨nBulmaperformansıdeg˘is¸iksenaryolarda
denenmis¸tir. Butezdegelis¸tirilensimu¨lasyonyo¨ntemininantendizilerininyo¨nbulmakarak-
teristiklerinianlamadaetkilioldug˘ugo¨sterilmis¸tir.
AnahtarKelimeler: Yo¨nBulma,KorelatifEnterferometre,Nu¨merikElektromanyetikSimu¨lasyon
Yo¨ntemleri,PlatformEtkileri
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Tomyfamily
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ACKNOWLEDGMENTS
I would like to thank my supervisor Prof. Dr. T. Engin Tuncer for his guidance, encourage-
mentandpatiencethroughoutthecompletionofthethesis.
IwouldliketothanktoDr. TansuFilik,YılmazKalkan,Dr. SerkanKaraku¨tu¨k,MetinAktas¸
andM.FatihBayramog˘lufortheirsupportandfriendshipduringmythesiswork.
IwouldliketothanktoTu¨bitakBideb,fortheirfinancialsupportduringmygraduatestudy.
Finally,Iwouldliketothanktomymotherforhersupporttofinishmythesiswork.
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TABLE OF CONTENTS
ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
O¨Z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
ACKNOWLEDGMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
TABLEOFCONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
LISTOFTABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
LISTOFFIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii
CHAPTERS
1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 DirectionFinding . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.1 HistoryofDirectionFinding . . . . . . . . . . . . . . . . 1
1.1.2 ClassicalandModernDirectionFindingTechniques . . . 2
1.2 DescriptionofThesisWork . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 DFSYSTEMCOMPONENTSANDNUMERICALELECTROMAGNETIC
COMPUTATIONALTOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 DFSystemComponents . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.1 FlowChartofSimulationMethodology . . . . . . . . . . 7
2.1.2 SignalModel . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.3 CorrelativeInterferometerMethod . . . . . . . . . . . . . 10
2.1.4 FlowChartofCorrelativeInterferometerMethodology . . 12
2.1.5 CubicSplineInterpolationMethod . . . . . . . . . . . . . 15
2.1.6 MultipathEffects . . . . . . . . . . . . . . . . . . . . . . 17
2.2 NumericalElectromagneticComputationalTools . . . . . . . . . . . 19
2.2.1 FEKOToolsandSimulationSettings. . . . . . . . . . . . 20
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3 WIDEBANDANTENNADFSYSTEM . . . . . . . . . . . . . . . . . . . . 22
3.1 AntennaModels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.1.1 DisconeAntennaModel . . . . . . . . . . . . . . . . . . 23
3.1.2 DipoleAntennaModel . . . . . . . . . . . . . . . . . . . 30
3.1.2.1 Band-1DipoleAntennaModel . . . . . . . . 30
3.1.2.2 Band-2DipoleAntennaModel . . . . . . . . 32
3.2 WidebandAntennaSimulationResults . . . . . . . . . . . . . . . . 35
3.2.1 Band-1Simulations . . . . . . . . . . . . . . . . . . . . . 36
3.2.2 Band-2Simulations . . . . . . . . . . . . . . . . . . . . . 45
3.3 Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4 DFSYSTEMONUAVWITHDIPOLEANTENNAS. . . . . . . . . . . . . 56
4.1 DipoleAntennaandUAVModel . . . . . . . . . . . . . . . . . . . 57
4.1.1 DipoleAntennaModel . . . . . . . . . . . . . . . . . . . 58
4.1.2 UAVFekoModelwithFourAntenna . . . . . . . . . . . 59
4.1.3 UAVFekoModelwithEightAntenna . . . . . . . . . . . 62
4.2 SimulationResultsfortheUAV . . . . . . . . . . . . . . . . . . . . 65
4.2.1 FourAntennaModelSimulationResults . . . . . . . . . . 66
4.2.2 EightAntennaModelSimulationResults . . . . . . . . . 74
4.3 Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
5 DFSYSTEMONSUVWITHMONOPOLEANTENNAS . . . . . . . . . . 84
5.1 SUVModel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
5.1.1 AntennaModel . . . . . . . . . . . . . . . . . . . . . . . 85
5.1.2 SUVFekoModel . . . . . . . . . . . . . . . . . . . . . . 86
5.2 SimulationResultsfortheSUV . . . . . . . . . . . . . . . . . . . . 91
5.2.1 PerfectElectricConductorvs. DielectricMedium . . . . . 92
5.3 BiasAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
5.3.1 PerfectElectricConductorvsDielectricMedium-1 . . . . 100
5.3.2 PerfectElectricConductorvsDielectricMedium-2 . . . . 107
5.4 Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
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