Analysis and Design of Transmitarray Antennas

155 Pages·2017·6 MB·English

by  Ahmed H. Abdelrahman

Analysis and Design of
Transmitarray Antennas
Ahmed H. Abdelrahman
UniversityofColoradoBoulder
Fan Yang
TsinghuaUniversity
Atef Z. Elsherbeni
ColoradoSchoolofMines
Payam Nayeri
ColoradoSchoolofMines
SYNTHESISLECTURESONANTENNAS#12
M
&C Morgan &cLaypool publishers
Copyright©2017byMorgan&Claypool
AnalysisandDesignofTransmitarrayAntennas
AhmedH.Abdelrahman,FanYang,AtefZ.Elsherbeni,andPayamNayeri
www.morganclaypool.com
ISBN:9781627058742 paperback
ISBN:9781627057066 ebook
DOI10.2200/S00749ED1V01Y201612ANT012
APublicationintheMorgan&ClaypoolPublishersseries
SYNTHESISLECTURESONANTENNAS
Lecture#12
SeriesEditor:ConstantineA.Balanis,ArizonaStateUniversity
SeriesISSN
Print1932-6076 Electronic1932-6084
ABSTRACT
In recent years, transmitarray antennas have attracted growing interest with many antenna re-
searchers.Transmitarrayscombinesbothopticalandantennaarraytheory,leadingtoalowpro-
filedesignwithhighgain,highradiationefficiency,andversatileradiationperformanceformany
wirelesscommunicationsystems.Inthisbook,comprehensiveanalysis,newmethodologies,and
noveldesignsoftransmitarrayantennasarepresented.
• Detailedanalysisforthedesignofplanarspace-fedarrayantennasispresented.ebasics
of aperture field distribution and the analysis of the array elements are described. e ra-
diationperformances(directivityandgain)arediscussedusingarraytheoryapproach,and
theimpactsofelementphaseerrorsaredemonstrated.
• eperformanceoftransmitarraydesignusingmultilayerfrequencyselectivesurfaces(M-
FSS) approach is carefully studied, and the transmission phase limit which are generally
independentfromtheselectionofaspecificelementshapeisrevealed.emaximumtrans-
missionphaserangeisdeterminedbasedonthenumberoflayers,substratepermittivity,and
theseparationsbetweenlayers.
• In order to reduce the transmitarray design complexity and cost, three different methods
havebeeninvestigated.Asaresult,onedesignisperformedusingquad-layercross-slotele-
mentswithnodielectricmaterialandanotherusingtriple-layerspiraldipoleelements.Both
designswerefabricatedandtestedatX-Bandfordeepspacecommunications.Furthermore,
the radiation pattern characteristics were studied under different feed polarization condi-
tionsandobliqueanglesofincidentfieldfromthefeed.
• New design methodologies are proposed to improve the bandwidth of transmitarray an-
tennas through the control of the transmission phase range of the elements. ese design
techniquesarevalidatedthroughthefabricationandtestingoftwoquad-layertransmitarray
antennasatKu-band.
• A single-feed quad-beam transmitarray antenna with 50 degrees elevation separation be-
tweenthebeamsisinvestigated,designed,fabricated,andtestedatKu-band.
In summary, various challenges in the analysis and design of transmitarray antennas are
addressedinthisbook.Newmethodologiestoimprovethebandwidthoftransmitarrayantennas
havebeendemonstrated.Severalprototypeshavebeenfabricatedandtested,demonstratingthe
desirablefeaturesandpotentialnewapplicationsoftransmitarrayantennas.
KEYWORDS
transmitarray antennas, frequency selective surfaces, multilayer aperture antennas,
highgainantennas,widebandtransmitarrayantennas,multibeamtransmitarrayan-
tennas
Contents
ListofFigures .....................................................xiii
ListofTables ...................................................... xxi
1 Introduction ....................................................... 1
1.1 TransmitarrayAntennaConcept ......................................1
1.2 ComparisonwithSomeRelatedAntennaTechnologies....................2
1.3 TransmitarrayDesignApproaches.....................................3
1.3.1 Multi-layerFrequencySelectiveSurfaces(M-FSS)..................3
1.3.2 Receiver-transmitterDesign....................................4
1.3.3 Metamaterial/TransformationApproach ..........................5
1.4 OverviewofResearchTopics.........................................5
2 Space-fedArrayDesignMethod ....................................... 7
2.1 PhaseDistributiononTransmitarrayAperture ...........................7
2.2 Unit-cellElementAnalysis ..........................................9
2.3 RadiationAnalysisusingtheArrayeory ..............................9
2.4 DirectivityCalculations ............................................13
2.4.1 Method1:NumericalIntegration ..............................13
2.4.2 Method2:UtilizationofBesselFunction ........................14
2.4.3 Method3:IlluminationEfficiency ..............................17
2.4.4 ComparisonBetweenthereeMethods ........................18
2.4.5 DirectivityBandwidth........................................18
2.5 AntennaGain....................................................19
2.5.1 SpilloverEfficiency ..........................................20
2.5.2 ElementLosses .............................................22
2.6 PhaseErrorAnalysis ..............................................23
2.6.1 DesignErrors ..............................................23
2.6.2 ApproximationsinUnit-cellAnalysis ...........................28
2.6.3 ManufacturingErrors ........................................28
3 AnalysisofMulti-layerTransmitarrayAntenna .......................... 33
3.1 Single-layerFSSAnalysis ..........................................34
3.1.1 eoreticalAnalysisofSingle-layerFSS .........................34
3.1.2 NumericalDemonstrationofSingle-layerFSS ....................36
3.1.3 Single-layerofDoubleSquareLoopElements ....................39
3.1.4 SingleConductorwithaSubstrateLayer.........................40
3.2 Double-layerFSSAnalysis .........................................44
3.2.1 eoreticalAnalysisofDouble-layerFSS ........................44
3.2.2 NumericalDemonstrationofDouble-layerFSS ...................46
3.3 Multi-layerFSSAnalysis ...........................................50
3.3.1 AnalyticalAnalysisofTriple-layerFSS ..........................50
3.3.2 NumericalDemonstrationofTriple-layerFSS ....................53
3.3.3 Quad-layerFSS.............................................55
4 AQuad-layerTransmitarrayAntennaUsingSlot-typeElements............ 57
4.1 Cross-slotTransmitarrayAntennaDesign .............................57
4.1.1 Cross-slotElementDesign....................................57
4.1.2 TransmitarrayDesignandMeasurements ........................59
4.2 DiscussiononObliqueIncidenceandFeedPolarizationEffects ............61
4.2.1 ElementPerformanceunderObliqueIncidence ...................61
4.2.2 ApertureDistributionandRadiationPattern......................62
5 DesignofTriple-layerTransmitarrayAntennas.......................... 69
5.1 IdenticalTriple-layerTransmitarrayAntenna ...........................70
5.1.1 SpiralDipoleElementDesign .................................70
5.1.2 TransmitarrayDesign ........................................73
5.1.3 ExperimentandDiscussion ...................................75
5.2 Non-identicalTriple-layerTransmitarrayAntenna.......................79
5.2.1 Non-identicalDouble-layerFSSAnalysis ........................79
5.2.2 Non-identicalTriple-layerFSSAnalysis .........................80
5.3 Double-layerUnit-cells ............................................90
6 WidebandTransmitarrayAntennas ................................... 95
6.1 BandwidthAnalysisofaTransmitarrayusingQuad-layerDoubleSquare
LoopElements ...................................................96
6.1.1 Unit-cellProperty ...........................................96
6.1.2 BandwidthPerformanceofTransmitarray ........................99
6.2 BandwidthPerformancewithDifferentReferencePhasesattheAperture
Center .........................................................101
6.3 ProperSelectionofElementPhaseRangeforImprovementof
TransmitarrayBandwidth..........................................103
6.4 ComparisonbetweenDifferentElementShapes........................105
6.5 PrototypeFabricationandMeasurements .............................108
7 Single-feedMulti-beamTransmitarrays............................... 115
7.1 DesignMethodologiesforSingle-feedMulti-beamTransmitarrayAntennas.115
7.2 DesignofKu-bandSingle-feedQuad-beamTransmitarrayAntennas ......116
7.3 PrototypeFabricationandMeasurements .............................118
7.4 TransmitarrayApproximationandPerformanceDiscussions ..............125
7.4.1 ObliqueIncidenceEffectoftheUnit-cellElement ................125
7.4.2 VariationsinDimensionsofNeighboringElements ...............126
7.4.3 PhaseErrorandMagnitudeLossEffectontheRadiationPatterns ...128
8 Conclusions...................................................... 135
8.1 ContributionsofthisBook ........................................135
8.2 FutureWork ....................................................136
A S-matrixofCascadedLayers ........................................ 139
Bibliography ..................................................... 141
List of Figures
1.1 Geometryofatransmitarrayantenna. ..................................2
1.2 Antennatechnologiesrelatedtotransmitarrays:(a)aplanarphasedarray,
(b)alensantenna,and(c)aplanarreflectarray. ...........................2
1.3 Multi-layerFSSconfiguration. .......................................4
1.4 Receiver-transmitterconfiguration. ....................................4
1.5 Contentofthebook. ...............................................6
2.1 Phasecompensationofamulti-layertransmittarrayantenna.................8
2.2 Exampleoftherequiredphasedistributioninacircularaperture
transmittarray......................................................8
2.3 A3Dmodelaquad-layertransmitarrayunit-cellinCSTMicrowaveStudio
software[27]. ....................................................10
2.4 Transmissioncoefficientofaquad-layerunit-cellat13.5GHz..............10
2.5 ecoordinatesystemofthetransmitarrayantenna. .....................11
2.6 Radiationpatternofa30 30circularapperturetransmitarrayantenna
(cid:2)
withabroadsidebeam. .............................................12
2.7 Directivitycalculationsofacircularaperturetransmitarrayantennausing
thenumericalintegrationmethod.....................................14
2.8 Directivityvs.frequencyof60 60rectangulartransmitarrayantenna........20
(cid:2)
2.9 Spilloverefficiencyanalysis. .........................................21
2.10 Sourcesofphaseerrors. ............................................23
2.11 Radiationpatternofacircularaperturetransmitarrayantennaatdifferent
quantizationphasevalues. ..........................................24
2.12 Transmitarrayantennagainvs.quantizationphase. ......................25
2.13 Phasedistributionofthetransmitarrayantennafordifferentquantization
phasevalues:(a)idealphasedistribution,(b)3-bitphasedistribution,
(c)2-bitphasedistribution,and(d)1-bitphasedistribution. ...............26
2.14 Radiationpatternofacircularaperturetransmitarrayantennaatdifferent
transmissionphaseranges. ..........................................27
2.15 Transmitarrayantennagainvs.limitedphaserange.......................27
2.16 Surfacedeformationon:(a)reflectarraysurfaceand(b)transmitarraysurface. .29
2.17 Feedpositionerrorofatransmitarrayantenna...........................30
2.18 Standardnormaldistributionfunction. ................................31
2.19 Effectofrandomphaseerroronthegainofatransmitarrayantenna. ........31
3.1 Single-layerwithaconductingelement. ...............................34
3.2 Transmissioncoefficientofasingle-layerconfiguration....................36
3.3 Unit-cellsof:(a)acrossdipoleand(b)asquareloop. .....................37
3.4 Transmissioncoefficientsofthesingle-layerelements:(a) S and
21
j j
(b) S ........................................................37
21
(cid:134)j j
3.5 Transmissioncoefficientpresentedonpolardiagramsfor:(a)acrossdipole,
(b)asquareloop,and(c)across-slotelements. ..........................38
3.6 Unit-cellofadoublesquareloopelement. .............................39
3.7 Transmissioncoefficientofthesingle-layerdoublesquareloopelement:
(a) S and S and(b)polarplot. ................................40
21 21
j j (cid:134)j j
3.8 Transmissioncoefficientofthesingle-layerdoublesquareloopelement
underobliqueincidenceangleof30 :(a) S ,(b) S ,
(cid:14) 21 21
j j (cid:134)j j
(c)perpendicularpolarizationinapolardiagram,and(d)parallel
polarizationinapolardiagram. ......................................41
3.9 Singleconductorthicksubstratelayer..................................41
3.10 Transmissioncoefficientofasingleconductorthicksubstratelayerfor
differentsubstrateelectricalthickness(cid:12)L at" 2:5. ...................42
d r
D
3.11 Transmissioncoefficientofasingleconductorthicksubstratelayerfor
differentsubstratepermitivity" at(cid:12)L 90 . .........................42
r d (cid:14)
D
3.12 Transmissioncofficientofasingleconductorlayerwhenreplacingthethick
substratebyanairgapfordifferent(cid:12)L values. .........................43
d
3.13 Simulationandanalyticalresultsofasingleconductorthicksubstratelayer
usingthedoublesquareloopshape:(a)fordifferentsubstrateelectrical
thickness(cid:12)L at" 2:5and(b)fordifferentsubstratepermittivity" at
d r r
D
(cid:12)L 90 .......................................................44
d (cid:14)
D
3.14 Double-layerFFSconfiguration. .....................................45
3.15 Transmissioncoefficientofthedouble-layerfordifferentdielectric
permitivitybyconstantelectricalthicknessof(cid:12)L 90 . .................45
d (cid:14)
D
3.16 Transmissioncoefficientofthedouble-layerfordifferentsubstrateelectrical
thicknessusingdielectricpermitivity" 1.............................46
r
D
3.17 Simulationandanalyticalresultsofadouble-layerconfigurationusingthe
doublesquareloopelementfordifferentdielectricpermittivitybutconstant
electricalthicknessof(cid:12)L 90 :(a)transmissionmagnitude,
d (cid:14)
D
(b)transmissionphase,and(c)polarplot. ..............................48
3.18 Simulationandanalyticalresultsofadouble-layerconfigurationusingthe
doublesquareloopelementfordifferentelectricalthicknessbutconstant
substratepermittivityof" 2:5:(a)(cid:12)L 60 ,(b)(cid:12)L 90 ,
r d (cid:14) d (cid:14)
D D D
(c)(cid:12)L 120 ,and(d)(cid:12)L 270 . ................................49
d (cid:14) d (cid:14)
D D
3.19 Simulationandanalyticalresultsofadouble-layerconfigurationusingthe
doublesquareloopelementfordifferentsubstratepermittivitybutconstant
substratethicknessofL (cid:21)0=4:(a)" 1.(cid:12)L 90 )and
d r d (cid:14)
D D D
(b)" 2:5.(cid:12)L 142:3 ). .......................................50
r d (cid:14)
D D
3.20 Simulationresultsofadouble-layerconfigurationusingthedoublesquare
loopelementforbothlosslessandlossymaterials.........................51
3.21 Triple-layerFSSconfiguration. ......................................51
3.22 Transmissioncoefficientsofthetriplelayerfordifferentsubstrateelectrical
thicknessusingdielectricpermittivity:(a)" 1and(b)" 2. ...........52
r r
D D
3.23 Transmissionphaserangeofatriple-layerFSSwithelectricalthickness
betweentheconductorlayersof(cid:12)L 90 .............................53
d (cid:14)
D
3.24 Simulationandanalyticalresultsofatriple-layerconfigurationusingthe
doublesquareloopelementfordifferentdielectricpermittivitybutconstant
electricalthicknessof(cid:12)L 90 :(a)transmissionmagnitude,
d (cid:14)
D
(b)transmissionphase,and(c)polarplot. ..............................54
3.25 Quad-layerFSSconfiguration. ......................................55
3.26 Transmissioncoefficientofthequad-layerFSSfor(cid:12)L 90 and" 1. ...55
d (cid:14) r
D D
3.27 Simulationandanalyticalresultsofthequad-layerconfigurationusingthe
doublesquareloopelementfor(cid:12)L 90 and" 1:(a)transmission
d (cid:14) r
D D
magnitude,(b)transmissionphase,and(c)polarplot. ....................56
4.1 Cross-slotelementunit-cell:(a)topviewand(b)sideview.................58
4.2 Transmissioncoefficientvs.theslotlengthL forthefouridenticallayers
s
oftheunit-cellshowninFig.4.1. ....................................58
4.3 Aquad-layercircularaperturetransmitarrayantenna:(a)transmitarray
maskand(b)pictureofthefabricatedquad-layertransmitarray..............59
4.4 Transmitarrayantennasetupforanearfieldmeasurement. ................60
4.5 Measuredandsimulatedradiationpattern,consideringonlynormal
incidenceplanewaveinthesimulationforallarrayelements................60
4.6 Transmitarrayantennameasuredgainvs.frequency.......................61
4.7 Transmissioncoefficientversusslotlengthatdifferentobliqueincidence
angles:(a)transmissionmagnitudeand(b)transmissionphase. .............62
4.8 etransmitarrayelementsilluminationbythefeedhorn..................63
4.9 Transmissioncoefficientofthedoublesquareloopelementatnormal
incidenceand30 obliqueangle:(a)transmissionmagnitudeand
(cid:14)
(b)transmissionphase. .............................................64
4.10 Obliqueincidencewavefromthefeedantennaonasamplearrayelement:
(a)3Dview,(b)topview(x-y plane),and(c)planeofincidenceview. .......65
4.11 Transmittedverticallypolarizedelectricfield:(a)withnormalincidence
planewaveapproximationand(b)withobliqueincidence. .................66
4.12 Measuredandsimulatedradiationpattern,consideringboththeoblique
incidenceanglesandthefeedpolarizationinthesimulationofeachelement
ofthearray. ......................................................66
5.1 Triple-layerunit-cell:(a)cross-dipoleshape,(b)spiral-dipoleshape,and
(c)triple-layerconfigurationoftheunit-cell.............................71
5.2 Transmissioncoefficientsofthetriple-layercross-dipoleandspiral-dipole
elements:(a)magnitudevs.theelementdimensionL,(b)phasevs.the
elementdimensionL,(c)phasemagnituderelationofthecross-slot
elementinapolardiagram,and(d)phasemagnituderelationofthe
cross-slotelementinapolardiagram. .................................72
5.3 Transmissioncoefficientvs.elementdimensionLunderdifferentincident
angles:(a)magnitudesand(b)phases. .................................74
5.4 Typicalgeometryofaprintedtransmitarrayantenna......................75
5.5 Transmitarrayaverageelementlossvs.aperturecenterelementphase. .......75
5.6 Circularaperturetransmitarrayantenna:(a)topviewpictureofthe
transmitarrayaperture,(b)elementstransmissionphasedistribution,
(c)elementstransmissionmagnitudedistribution,and(d)relative
illuminationfromthefeedonthetransmitarrayelements. .................76
5.7 Transmitarrayantennasetupforanearfieldmeasurement. ................77
5.8 MeasuredH-plane(xz plane)andE-plane(yz plane)radiationpatterns. ....77