status and progress of paf technology
TRANSCRIPT
CSIROASTRONOMYANDSPACESCIENCE
PhasedArrayFeedDevelopmentUpdate
CSIRO– TechnologiesforRadioAstronomy,ASKAPTeam,SKAPAFGroupandAPERTIFTeam
MarkBowen,AlexDunning,DougHayman,Kanapathippillai Jeganathan,SeanSevers,RobShaw,BruceVeidt,LisaLoche,andWim vanCappellen
07March2016
Outline• PAFInstruments
Ø ASKAPØ Parkes 64m– BonnPAF(MPIfR)Ø APERTIF
• SKAPAFDevelopment – SKADish• PhasedArrayFeedArrayDevelopments
Ø AFADØ CryoPAF4Ø PHAROSØ ChequerboardArrayØ RocketArray
• ComparisonofcurrentPAFs• TheFuture
PhasedArrayFeedDevelopmentUpdate|MarkBowen|Page2
ASKAP– AustralianSKAPathfinderA Wide Field-of-View Radio Telescope
Number of dishes 36 Dish diameter 12 mMax baseline 6kmResolution 10” (6km array), 30” (2km core)
Sensitivity 70 m2/KField of View 30 deg2
Speed 1.5x105 m4/K2.deg2
Observing frequency 700 – 1800 MHzProcessed Bandwidth 300 MHzSpectral Channels 16,000Phased Array Feeds 188 elements (94 dual polarisation)
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• Boolardy EngineeringTestArray(BETA)Ø DecommissionedFebruary2016Ø 6antennasfittedwithMk.IChequerboardPAFsØ Conversionandbasebandsamplingatantenna
• ASKAPDesignEnhancement (ADE)Ø 9antennascurrentlyoutfittedØ Mk.IIChequerboardPhasedArrayFeed/LNAsØ Directsamplingatcentralsite
ASKAP– AustralianSKAPathfinder
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ASKAP– ScienceCommissioning• First25BeamImage– FullASKAPFoV
Ø Centrefrequency– 850MHzØ Bandwidth– 48MHzØ 5antennas– Mk.IIPAFsfittedØ 25Beams– ASKAPFoV atthisfrequencyØ 30squaredegrees
The image was produced in a 12 hour observation of theApus test field using 5 Mk. II Phased Array Feeds.
The beam footprint as made up of 25 beams, in a 5 x 5square, and is the first image to instantaneously coverapproximately 30 square degrees – that is, the full ASKAPfield of view.
The data for the observation were calibrated and imagedon the ASKAP real time computer, Galaxy, located at thePawsey supercomputing centre in Perth, WesternAustralia.
Image Credit: Josh Marvil
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Parkes 64m– BonnPAF(MPI)• ASKAPPAF(Mk.II)builtbyCSIROforMPIfR
Ø ASKAPDigitiserandBeamformerØ GPUCorrelatorØ ModifiedRFsignalchain– Additionalfilters(RFI)
• CommissioningonParkes 64mantennaØ ReplacesParkes multibeam receiver(13beam)Ø Installation– February2016Ø Commissioning/softwaredevelopmentØ Removal– September2016Ø InstallationonEfflesberg – late2016
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Frequencyrange 1130– 1750MHzInstantaneousbandwidth 300MHzChannelbandwidth 12kHzPolarization DuallinearReflectors 12x25mBaselines 36to2412m
Systemtemperature 70KApertureefficiency 75%Simultaneousbeams 37dualpolFieldofview 8deg2
“Surveyspeedincrease” 17x
APERTIFspecifications
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• 12dishesmechanicallyupgraded• 6dishescurrentlyfullyinstalled• 6dishesreadyforhardware• NoiseSourceSysteminstalledforonedish
• HFcabinreadyforcorrelator
• Softwareverification
• Correlatorverification(à firstfringes)
• APERTIF-6softwareready(tocontrolinstrument)
StatusAPERTIFuptonow
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• Commissioning APERTIF-6
• APERTIF-12Installation• Hardwareforanother6dishes(dualpolarized)
• Furtherdevelopment ofcorrelatorfirmware
• APERTIF-12softwaredevelopment (usersoftware)(expectedendof2016)
• StartScienceCommissioning(April2016)
• FirstscienceAPERTIF2017
Currentlyongoingandfuture
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VerificationCorrelatorFirmwareà FirstFringes
• Usingskyinputdata,verify• Correctcross-correlationproduct
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SKAPAFDevelopment– SKADishCSIROPAFDesign
• Chequerboardarray• AustralianSKAPathfinder(ASKAP)Mk.II• RFoverFibresignaltransport• 650– 1670MHzband(SKA- Band2)
NRCPAFDesign• ThickVivaldiArray• AdvancedFocalArrayDemonstrator(AFAD)• Cryogeniccooling(CryoPAF)• 1.5– 4.0Hzband(SKA- Band3)
Credit: A. Chippendale, CSIRO
Credit: B. Veidt, NRC Canada
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AFAD– NRCCanadaKeyParameters
• FrequencyRange:0.75– 1.5GHz• ElementSpacing:100mm(λ/2)• ElementThickness: 5mm• TaperLength:113mm• SlotWidth:3mm• OverallLength:158mm• NumberofElements: 41• ElementMass: 165g
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MeasuredPerformancewithCMOSLNAs
• MeasuredperformanceoftheAFADArrayinaperturearraymodeusingtheNRCHot/ColdTestFacility(HCTF)locatedatDRAO,Penticton.
• TheAFADArraycomprisedof9CMOSLNAsincentreofthearray;theremaining32arrayelementshavecommercialHEMTLNAs.
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PAF Development - NRCConclusions• ObtainedgoodresultswithCMOSLNAsincentrearray
FutureWork• Constructa96element arraywithallelements usingCMOSLNAs• Singlepieceelement design• Digitalbeamformer• DemonstratearrayonDVA-1dishwithoffsetGregorianoptics
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CryoPAF4– NRCCanadaHistory
• 2014:SKADISHconsortium,“Band3”• 2015:NRCproject,newfrequency
Goals• Frequency:2.80– 5.18GHz• Systemtemperature:16K• Elements: Vivaldi– 96active(140intotal)• Cryogenicallycooledelements andLNAs(15K)• Duallinearpolarization• Digitalbackend– 36beamsat500MHz• SampledatRF
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SystemDescription
Description• Compositeradome• Infraredfilters/heatshields&metal
radiationshields• 140element arrayofall- metalVivaldis• Elements: Vivaldi– 96active(140in
total)• Elements andLNAscooledto15K• 3.5Knoise3-stageLNAs,40dBgain• Receiverpackageincludes filteringand
postLNAamplification– Roomtemp• Digitalbackend– 36beamsat500MHz• SampledatRF
PhasedArrayFeedDevelopmentUpdate|MarkBowen|Page16
Thetotalreceivernoisetemperature is10.82K,whichwhenaddedtothecosmicbackground,atmosphere,andapproximatespilloverresults in18.52Ktotalsystemtemperature.
EstimatedSystemTemperature
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PowerBudget• Coldheads
• SinglestageGifford-McMahoncompressedheliumforcoolingLNAarray.5Wat15Kcapacity,0.29%efficiency,1.7kWpower.
• Singlestagepulse-tubecompressedheliumforheatsinking96dewar – DBEcoaxialcables.45Wat70K,0.65%efficiency,700Wpower.
• Heliumlines• Heliumcompressor
• Singlecompressortodeliver2.4kW• HeatShields
• RFtransparentheatshieldsbetweenradomeandantennaarraytoreflectinfraredradiation.
• Concentricthinmetalcylindersat15K,70K,300K- thermalinsulationtomostcriticalcomponents:LNAs
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PHAROS– JBCO,ASTRON,INAF• Cryogenicreceiver
• MMIC4-8GHzLNA(ASTRON)
• Analog MMICbasedbeamformer
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ChequerboardArray- CSIROOngoingWork
Ø ReducingPAFTsys– ReductionofTLNA =5K– 7KoverASKAPMkIILNAachievedinlaboratory
Ø UnderstandingoffeedwirelossanddielectriceffectsØ AdditionaldevicesbeingevaluatedforMk.IVandbeyondØ Improvedelement geometry(particularlyedgeelements)
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RocketArray– CSIROCSIROSKAPAFProgram
• Initiallyfocussedon650– 1670MHz(band2)• CommonRFsignalchain(Bands1,2,3)• Reducingsystemtemperature(TLNA)• OngoingevolutionofASKAPfeedpackage
(Mk.II→Mk.III→Mk.?)• ‘Rocket’elementdemonstrated5x4array
(40Elements)
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ElementandLNADesign• Elementbasedonaconicalsolidofrevolution• Edgeelements designedtoreducetheeffectoftheedge
discontinuity• Feedlinelossminimised• BalancedLNA– Differentialimpedance180Ω• CommercialHEMTLNA– TriQuint TQP3M939&TQP3M9040• 5x4arrayconstructedasproof-of-concept
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• CommonRFsystemarchitecture– SKAbands(1,2,3)Ø RFoverFibre(RFoF)forsignaltransport(ASKAP)Ø Integrated8channelassemblycompletedandtestedØ AllowsdirectinterfacingwithASKAPdigitalbackend
0 500 1000 1500 2000 2500 3000 3500 4000Frequency (MHz)
RF chain with and without Equalizer
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20585.1 MHz12.4 dB
1671 MHz5.74 dB
646 MHz6.32 dB
DB(|S(2,1)|)TxRx__30dBpad_without Equalizer
DB(|S(2,1)|)TxRx__30dBpad_with equalizer
200 400 600 800 1000 1200 1400 1600 1800 2000Frequency (MHz)
Equal_3A_measured
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
01754 MHz-1.571 dB
1153 MHz-5.51 dB368.1 MHz
-6.328 dB650.4 MHz-6.245 dB
1672 MHz-2.331 dB
DB(|S(2,1)|) (L)Equalizer_3A
DB(|S(1,1)|) (R)Equalizer_3A
PAF3 Eelectronics
RFoF txLNA Amp FIL
PAF1 Eelectronics
RFoF txLNA Amp FIL
PAF2 Eelectronics
RFoF txLNA Amp FIL
PAF (Band) selection
Pin Diode
Band control
ADCAmp FIL
RFoF Receiver
To PPFB / BF
Simplified System Block Diagram(Y. Chung 2015)
Prototype RF Signal Chain Gain
RFSignalChain• Leverageoffotherdevelopments– SKA
PhasedArrayFeedDevelopmentUpdate|MarkBowen|Page23
• MeasurementusingmaxSNRbeamweights,usingtheParkes TestFacility– BETAdigitalbackend.• Measurement“calibrated’usingASKAP(Mk.II)referencearray.• GapsinthemeasurementsarecausedbyRFIwhilsttheverticaldisplacementisduetothe
measurementsystem.
MeasuredPerformance– Parkes TestFacilityMeasuredNoiseTemperature– RocketArray
PhasedArrayFeedDevelopmentUpdate|MarkBowen|Page24
FutureWork• Hot/Coldloadtesting(LN2)– ASKAPMk.IIdigitalbackend(Mar2016)• InstallationonParkes 64mantenna– BonnPAFbackend(Sep2016)• LNAdevelopment– Parkes Ultra-WidebandReceiver• Investigatecryogenicsystemissues
Ø CooledelementsØ VacuumwindowØ Hermeticfeedthrus
• SamplingattheFocus
PhasedArrayFeedDevelopmentUpdate|MarkBowen|Page25
• Measurements“calibrated’usingASKAP(Mk.II)referencearray.• GapsinthemeasurementsarecausedbyRFI.
Performance– RoomTemperaturePAFs
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CSIROStrategicDevelopment• EnhanceexistingAustraliaTelescopeNationalFacility(ATNF)Instruments• ReductioninPAFTsysachievedinSKAworkincorporatedintoASKAP• ParticipateinSKAPAFAIP• Continuecollaborativemeasurementprogram(NRC,ASTRON,JBCO,INAF)• EngagementwithbroaderPAFcommunity
• CryogenicallycooledPAFforParkesØ RocketarrayelementgeometryØ RFI/EMIconsiderationsØ Samplingatthefocus
• Increasebandwidth>2.5:1• HighfrequencyPAF– 22GHz• Designformanufacture
Ø Cost,MassØ Powerconsumption
PhasedArrayFeedDevelopmentUpdate|MarkBowen|Page27
TheFuture
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RadioAstronomyinGeneral• PAFsonlargesingledishes– Parkes,Effellsberg, Lovell,SRT,Arecibo&GBT• CryogenicPAFs• HighfrequencyPAFs(2GHz– 20GHz)• Continuecollaborativeprograms(NRC,ASTRON,JBCO,INAF,CSIRO,NRAO)• PAFsontheSKA
CSIROASTRONOMYANDSPACESCIENCE
CSIROAstronomyandSpaceScienceMarkBowenGroupLeader– [email protected]
We acknowledge the Wajarri Yamatji people as thetraditional owners of the Murchison Radio Observatory site.
ReferencesA.Chippendale,D.HaymanandS.Hay,“MeasuringNoiseTemperaturesofPhased-ArrayAntennasforAstronomy”,PublicationsoftheAstronomicalSocietyofAustralia,doi:10.1017/pas.2014.
R.ShawandS.Hay,“TransistorNoiseCharacterizationforanSKALow-NoiseAmplifier”,inProc.9thEuropeanConferenceonAntennasandPropagation(EuCAP),April12-17,2015,Lisbon,Portugal.
A.J,Beaulieu,L.Belostotski,T.Burgess,B.Veidt andJ.Haslet,“NoisePerformanceofaPhased-ArrayFeedwithCMOSLow-NoiseAmplifiers”,Accepted,DOI10.1109/LAWP.2016.2528818,IEEEAntennasandWirelessPropegation Letters.
Dunning,M.A.Bowen,D.Hayman,J.Kanapathippillia,H.Kanoniuk,R.ShawandS.Severs,“TheDevelopmentofaWideband‘Rocket’PhasedArrayFeed,”Submitted,46thEuropeanMicrowaveConference(EuMC),October4-6,2016,London,UK.
Veidt etal.,“Noise PerformanceofaPhased-ArrayFeedComposedofThickVivaldiElementswithEmbeddedLow-NoiseAmplifiers”,EuCAP 2015