design of circularly polarized microstrip antenna using truncated corner method
A Ka-Band (26 GHz) Circularly Polarized 2x2 Microstrip ...
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A Ka - Band (26 GHz) Circularly Polarized 2x2 Microstrip Patch Sub - Array with Compact Feed Andrew Chrysler Cynthia Furse University of Utah Rainee Simons Félix Miranda NASA Glenn Research Center
Transcript of A Ka-Band (26 GHz) Circularly Polarized 2x2 Microstrip ...
AKa-Band(26GHz)CircularlyPolarized2x2MicrostripPatchSub-ArraywithCompactFeed
AndrewChryslerCynthiaFurse
UniversityofUtah
RaineeSimonsFélixMiranda
NASAGlennResearchCenter
Motivation&Objective§ Designa26GHz,Ka bandReflectorAntennaFeedtosupportnext-generationSCaNarchitecture§ Lightweight§ Small§ Durable§ CircularPolarized
CircularPolarized(CP),TruncatedCornerPatchAntennas
Haneishi,M.andS.Yoshida,“ADesignMethodofCircularlyPolarizedRectangularMicrostripAntennabyOne-PointFeed,”inMicrostripAntennaDesign,K.C.GuptaandABenalla(Eds.),ArtechHouse,Norwood,MA,1988,pp.313-321
Originallyfrom1981,Reprintedin1988 ??? 2017,
Millimeterwave
frequencies
9GHz
3.1GHz
P.SharmaandK.Gupta,"Analysisandoptimizeddesignofsinglefeedcircularlypolarizedmicrostripantennas,"in IEEETransactionsonAntennasandPropagation,vol.31,no.6,pp.949-955,November1983.
Explorechangesthatoccurintheantennadesignasthefrequencyisincreasedto26GHz
MajorTopics
§SingleElement,TruncatedCorner,CircularPolarizedPatchAntenna§FeedNetwork§2x2SubArray
MajorTopics
§SingleElement,TruncatedCorner,CircularPolarizedPatchAntenna§FeedNetwork§2x2SubArray
TruncatedCornerscreateCircularPolarization(CP)inthePatchAntenna
SubstrateThickness,tCornerTruncation
producesCP
Rogers5880ɛr=2.2
WavelengthinsideSubstrate,λd
TruncationandS11 Design
Rogers5880• LowLoss,εr =2.2• ManyThicknessAvailable• CommonSubstrate
TruncationAmount,a• KnownRelationshiptoS11
• UnknownRelationshiptoAxialRatio(AR)
DecreasingSubstrateThickness(Rogers5880)
10mil,Rogers5880(εr =2.2)TruncationVaried,50Ω MicrostripFeed
GreaterTruncation
Simulation*UnderpredictsMeasuredResonantFrequency
10mil,Rogers5880(εr =2.2)TruncationVaried,50Ω MicrostripFeed
MeasuredAR SimulatedAR
Simulation*UnderpredictsMeasuredARBandwidth
a[mm]
3dBBandwidth
0.50 4.22%
0.57 6.73%
0.60 2.07%
0.74 1.78%
a[mm]
3dBBandwidth
0.50 1.37%
0.57 1.37%
0.60 0.78%
0.74 -----
10mil,Rogers5880(εr =2.2)TruncationVaried,50Ω MicrostripFeed
TheBestARandtheBestS11donotoccuratthesamefrequency
26.2GHz
25.3GHz
§Effectof§SubstrateThickness§SubstrateDielectricConstant§AntennaDesignFrequency
§Effectof§SubstrateThickness§SubstrateDielectricConstant§DesignFrequency
SubstrateThickness,t
SubstrateThicknessVariationattheKa Band(26GHz)
Rogers5880
SubstrateThickness
L[mm]
a[mm]
λd[mm] t/λd
AR3dBBandwidth
5mil 3.83 0.34 7.8 0.016 0.47%
10mil 3.75 0.49 7.8 0.033 1.19%
20mil 3.56 0.68 7.8 0.065 2.47%DesignChoice
AR&S11Mismatch
§Effectof§SubstrateThickness
§DesignFrequency§SubstrateDielectricConstant
10mil,Rogers5880(εr =2.2)FrequencyVaried(Simulation)
S11 BestAxialRatio
Frequency L[mm]
a[mm]
λd[mm]
t/λd AR3dBBandwidth
2.5GHz(SBand) 40.4 1.563 80.9 0.12 --
6GHz(CBandCenter) 16.7 1.011 33.7 0.30 --
10GHz(XBandCenter) 10.0 0.784 20.2 0.50 0.05%
15GHz(KuBandCenter) 6.6 0.641 13.5 0.74 0.66%
26GHz(KaBand) 3.7 0.487 7.8 0.87 1.19%
AllAntennasFedwith50ΩAllTruncationsdesignedfor-10dB
SurfaceCurrentatCenterFrequency10mil,Rogers5880
SBand2.5GHz
Ka Band25.5GHzAR<1dB
LeftHandandRightHandCPKa Band
LHCP RHCP
SubstrateThicknessVariationOverSeveralFrequencyBands(Simulation)
S11 BestAxialRatio
§Effectof§SubstrateThickness§DesignFrequency
§SubstrateDielectricConstant Ɛr =???
10mil,Rogers6006(εr =6.15)
S11 BestAxialRatio
Frequency[GHz]
L[mm]
a[mm]
λd[mm]
t/λd
2.5 (SBand) 24.2 0.67 48.4 0.0052
6 (CBand) 10.1 0.44 20.2 0.013
10 (XBand) 6.0 0.34 12.1 0.021
15 (KuBand) 4.0 0.29 8.1 0.032
26 (KaBand) 2.3 0.22 4.7 0.055
40 (VBand) 1.4 0.18 3.0 0.084
AllAntennasFedwith50ΩAllTruncationsdesignedfor-10dB
Sub-Topics
§SingleElement,TruncatedCornerPatchAntenna§PatchDesign§ InitialMeasurements§Effectof:
§ SubstrateThickness§ SubstrateDielectricConstant§ DesignFrequency
§DesignSuggestiontoEliminateS11 &ARMismatch
PossibleMethodforHighFrequencyS11 andARAlignment
L=3.749mm
Asymmetric
1.28% 1.57% 1.60%
3dBBandwidth
AsymmetricPatchMatchedWithλ/4Transformer
L=3.749mmW=3.674mm
§SingleElement,TruncatedCornerPatchAntenna
§FeedNetwork§2x2SubArray
FeedNetworkDesign
§CircularPolarizationImproved§SequentialRotation
§ A90° GeometricRotation§SequentialPhase
§ A90° PhaseRotation
SequentialRotation,90°
SequentialPhase,90°
90° ElectricalLength
Ka BandFeedNetworkDesign
CompactFeedNetwork
TraditionalFeedNetwork
UnwieldyFeedLinesandλ/4TransformersIncreaseFootprintandmayRestrictn xnArrayDesign
CleverUseofλ/4LineLengthsAllowsUniformLineWidthandCompactDesign
S. K. Lin and Y. C. Lin, "A Compact Sequential-Phase Feed Using Uniform Transmission Lines for Circularly Polarized Sequential-Rotation Arrays," in IEEE Transactions on Antennas and Propagation, vol. 59, no. 7, pp. 2721-2724, July 2011.
CornerTruncation
Footprint:199mm2 Footprint:375mm2
Ka BandFeedNetworkDesign
λ/4
3λ/4λ/4transformersmatchimpedanceatbranches
Ka BandFeedNetworkDesign
90°
270°
270° +φ 90°+φ
Ka BandFeedNetworkDesign
90°
270°
270° +φ 90°+φ
90°+θ
θ
θ
90°+θ
90°+θ
90°+θ
θ
θ
ElectricalDistanceFromFirstTeeJunction
90°+θ
180°+θ270°+θ
360°+θ
90°+φ+θ
180°+φ+θ270°+φ+θ
360°+φ+θ
§SingleElement,TruncatedCornerPatchAntenna§FeedNetwork§2x2SubArray
2x2SubArray,10mil,Rogers5880a =0.530mm
LHCP25.7GHz
RHCP25.7GHz
2x2SubArray,10mil,Rogers5880a =0.530mm
LHCP27.1GHz
RHCP27.1GHz
Conclusion&FutureWorks
§IdealantennaswillhavegoodoverlapinS11 andARbandwidth
§Inadditiontotheknowndesignequations,goodchoiceinsubstratethicknessanddielectricconstantisrequired
§Thecompactsub-arrayoffersanicesizereduction,butcouplingmayreducetheCPperformance
LHCP27.1GHz
RHCP27.1GHz
