status and progress of paf technology

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)


• Boolardy EngineeringTestArray(BETA)Ø DecommissionedFebruary2016Ø 6antennasfittedwithMk.IChequerboardPAFsØ Conversionandbasebandsamplingatantenna

• ASKAPDesignEnhancement (ADE)Ø 9antennascurrentlyoutfittedØ Mk.IIChequerboardPhasedArrayFeed/LNAsØ Directsamplingatcentralsite

ASKAP– AustralianSKAPathfinder


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


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


Frequencyrange 1130– 1750MHzInstantaneousbandwidth 300MHzChannelbandwidth 12kHzPolarization DuallinearReflectors 12x25mBaselines 36to2412m

Systemtemperature 70KApertureefficiency 75%Simultaneousbeams 37dualpolFieldofview 8deg2

“Surveyspeedincrease” 17x

APERTIFspecifications


• 12dishesmechanicallyupgraded• 6dishescurrentlyfullyinstalled• 6dishesreadyforhardware• NoiseSourceSysteminstalledforonedish

• HFcabinreadyforcorrelator

• Softwareverification

• Correlatorverification(à firstfringes)

• APERTIF-6softwareready(tocontrolinstrument)

StatusAPERTIFuptonow


• Commissioning APERTIF-6

• APERTIF-12Installation• Hardwareforanother6dishes(dualpolarized)

• Furtherdevelopment ofcorrelatorfirmware

• APERTIF-12softwaredevelopment (usersoftware)(expectedendof2016)

• StartScienceCommissioning(April2016)

• FirstscienceAPERTIF2017

Currentlyongoingandfuture


VerificationCorrelatorFirmwareà FirstFringes

• Usingskyinputdata,verify• Correctcross-correlationproduct


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


AFAD– NRCCanadaKeyParameters

• FrequencyRange:0.75– 1.5GHz• ElementSpacing:100mm(λ/2)• ElementThickness: 5mm• TaperLength:113mm• SlotWidth:3mm• OverallLength:158mm• NumberofElements: 41• ElementMass: 165g


MeasuredPerformancewithCMOSLNAs

• MeasuredperformanceoftheAFADArrayinaperturearraymodeusingtheNRCHot/ColdTestFacility(HCTF)locatedatDRAO,Penticton.

• TheAFADArraycomprisedof9CMOSLNAsincentreofthearray;theremaining32arrayelementshavecommercialHEMTLNAs.


PAF Development - NRCConclusions• ObtainedgoodresultswithCMOSLNAsincentrearray

FutureWork• Constructa96element arraywithallelements usingCMOSLNAs• Singlepieceelement design• Digitalbeamformer• DemonstratearrayonDVA-1dishwithoffsetGregorianoptics


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


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


Thetotalreceivernoisetemperature is10.82K,whichwhenaddedtothecosmicbackground,atmosphere,andapproximatespilloverresults in18.52Ktotalsystemtemperature.

EstimatedSystemTemperature


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


PHAROS– JBCO,ASTRON,INAF• Cryogenicreceiver

• MMIC4-8GHzLNA(ASTRON)

• Analog MMICbasedbeamformer


ChequerboardArray- CSIROOngoingWork

Ø ReducingPAFTsys– ReductionofTLNA =5K– 7KoverASKAPMkIILNAachievedinlaboratory

Ø UnderstandingoffeedwirelossanddielectriceffectsØ AdditionaldevicesbeingevaluatedforMk.IVandbeyondØ Improvedelement geometry(particularlyedgeelements)


RocketArray– CSIROCSIROSKAPAFProgram

• Initiallyfocussedon650– 1670MHz(band2)• CommonRFsignalchain(Bands1,2,3)• Reducingsystemtemperature(TLNA)• OngoingevolutionofASKAPfeedpackage

(Mk.II→Mk.III→Mk.?)• ‘Rocket’elementdemonstrated5x4array

(40Elements)


ElementandLNADesign• Elementbasedonaconicalsolidofrevolution• Edgeelements designedtoreducetheeffectoftheedge

discontinuity• Feedlinelossminimised• BalancedLNA– Differentialimpedance180Ω• CommercialHEMTLNA– TriQuint TQP3M939&TQP3M9040• 5x4arrayconstructedasproof-of-concept


• 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


• MeasurementusingmaxSNRbeamweights,usingtheParkes TestFacility– BETAdigitalbackend.• Measurement“calibrated’usingASKAP(Mk.II)referencearray.• GapsinthemeasurementsarecausedbyRFIwhilsttheverticaldisplacementisduetothe

measurementsystem.

MeasuredPerformance– Parkes TestFacilityMeasuredNoiseTemperature– RocketArray


FutureWork• Hot/Coldloadtesting(LN2)– ASKAPMk.IIdigitalbackend(Mar2016)• InstallationonParkes 64mantenna– BonnPAFbackend(Sep2016)• LNAdevelopment– Parkes Ultra-WidebandReceiver• Investigatecryogenicsystemissues

Ø CooledelementsØ VacuumwindowØ Hermeticfeedthrus

• SamplingattheFocus


• Measurements“calibrated’usingASKAP(Mk.II)referencearray.• GapsinthemeasurementsarecausedbyRFI.

Performance– RoomTemperaturePAFs


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


TheFuture


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

status and progress of paf technology

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