Phased Array Feeds for Parkes. Robert Braun Science with 50 Years Young

Transcription

1 Phased Array Feeds for Parkes Robert Braun Science with 50 Years Young

2 Outline PAFs in the SKA context PAFSKA activities Apertif, BYU, NRAO, NAIC, DRAO, ASKAP ASKAP PAF MkI ASKAP PAF MkII Parkes: a PAF prototype/science test-bed

3 PAFs in the SKA context SKA Dish array specifications: 0.45 ~10 GHz (Phase1) ~25 GHz (Phase2) Need to define feed/receiver modules, reserve focus real estate that insures 50+ year upgrade lifetime, eg GHz ~ 1.5x1.5 m B GHz ~ 1x1 m B GHz ~ 0.5x0.5 m B GHz ~ 0.25x0.25 m B GHz ~ 0.13x0.13 m B5 Need to be PAF-ready when cost effective

4 Getting more from each antenna Reflector Collects

5 Getting more from each antenna Reflector Collects Phased Array Feed collects more (~every λ/2)

6 Getting more from each antenna Reflector Collects Phased Array Feed collects more (~every λ/2) allows corrections

7 PAFSKA Activities: IEEE-TAP Special Issue - June 2011 phased array feeds 8 papers

8 PAFSKA Activities: Apertif ( ( Prototype Vivaldi PAF installed at WSRT Van Cappellen et al. 2011, URSI GASS2011 *+!),-.( /01,2#0&,$% *+*6!/$06 "#$%&'(%) 5 " )0&0!%(&<$#= ;$##(10&$# ABB1,%(! C#$/(--,%? 9(/(,:(# $/01!;$%&#$1!D%,& 5 " 4,-.!1(:(1! C#$/(--,%? /$%&#$1!%(&<$#= "#(FG(%/H!0%)!&,I(! -&0%)0#) ;$%&#$1!@!D-(#!E%&(#B0/( (((((( ( "#$%&'!()!*+,-./"!01234!5#6$&67!81'9:;!6<5!6!=&2:2:>='!+*"!#<?:611'5!#<!:@'!AB-.!8&#$@:;)!,

9 PAFSKA Activities: Apertif Prototype Vivaldi PAF installed at WSRT Van Cappellen et al. 2011, URSI GASS2011!!!!!!!"#$%&'()'*&+,$%&-'%+-"+."/0'1+..&%0,'/0'.2&',34'/5'6('78!'&9&:&0.,';2&%&'&+<2'1+0&9':&+,$%&,'6=6'-&#%&&,'

10 PAFSKA Activities: Apertif Prototype Vivaldi PAF installed at WSRT Van Cappellen et al. 2011, URSI GASS2011 High efficiency illumination, η B ~ 0.75, cf. horn η B ~ 0.55!!!!!!!!!!!!!!!!!"#$%&'()'!%*+,'-"&.'*/',0&'%&/1&2,*%'31&/,45'67#+",$8&'*/',0&'%&/1&2,*%'"11$6"+7,"*+'*/'7'0*%+'/&&8'32&+,%&4'' 7+8'9:!'3%"#0,4)'!!!!!!!!!!!!!!!!!!!!

11 PAFSKA Activities: Apertif Prototype Vivaldi PAF installed at WSRT Van Cappellen et al. 2011, URSI GASS2011 Current performance: T sys /η ~ 89 K, final < 73 K!"#$%&';)'<&7=$%&8':&>?=@='*/'7+'*+A7B"='9:!'C&76)'

12 PAFSKA Activities: Apertif Prototype Vivaldi PAF installed at WSRT Van Cappellen et al. 2011, URSI GASS2011 Standing wave reduced by > 20 db with PAF $ $ $!"#$%&'()'*&+,$%&-',&.,"/"0"/1'0&%,$,'2%&3$&.41'52'+'65%.72&-'-",6'89&2/:'+.-'+',".#9&';<!'&9&=&./'8%"#6/:)'' <99'9".&,'+%&'.5%=+9">&-'/5'$."/1'=&+.)' #

13 PAFSKA Activities: Cortes/NAIC/BYU National Astronomy and Ionosphere Center N')O'8".$,' L-Band N b! b BW A eff T SYS A EFF / T SYS [deg 2 ] [MHz] [m 2 ] [K] [m 2 /K] SVS/ AO SVS AO '8".$'9: ;< '='2631>32 27? '@"A '$ B 'C 71 '-DE' 1 ALFA AO FPA !"#$%&'()#*+,'-''-./0'1233' 4"56'7'

14 PAFSKA Activities: Cortes/NAIC/BYU 8*'*9"':;.<)#$' National Astronomy and Ionosphere Center!"#$%&'()#*+,'-''-./0'1233' 4"56'7'

15 PAFSKA Activities: Cortes/NAIC/BYU National Astronomy and Ionosphere Center ()&:"A*'B' B4';9=*"#F;).$' G"H)&'' ;9#,*'>*.8"'M2C'!"#$%&'()#*+,'-''-./0'1233' 4"56'7'

16 ASKAP PAFs m dishes 30 deg 2 FOV 50 K T sys MHz 300 MHz IF BW 2 Tb/s/antenna Digital beamforming Online imaging

17 Connected Chequerboard Array Advantages Low receiver noise high matching/radiation efficiencies High bandwidth 2.6:1 Easy/robust manufacture weather shielded temp. stabilised to 25 C could be cryo-cooled

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21 ASKAP MkI PAF

22 ASKAP Mk I PAF

23 Connected Chequerboard Array Overview Dense array matched to low-noise amplifiers (LNAs) Inherently broadband Self complementary Z 377 Ω Complete sampling of focal region fields Digital beamformer LNA + Conversion + Filtering Weighted (complex) sum of inputs Hay, S.G. and O Sullivan, J.D., Radio Science, 43, RS6S04, Hay, S.G., O Sullivan, J.D. and Mittra, R., IEEE TAP, 59, 3, 2011.

24 Parkes

25 ASKAP PAF MkI (Early Measurements) Aperture-Plane Array T rec for Boresight Beam Sensitivity matching conditions: Hay, IJMOT 5,6,2010 & ICEAA Measurement: unpublished

26 ASKAP PAF MkI (Early Measurements) Focal-Plane Array T sys /η for Boresight Beam T sys /η (K) Beamformed System Temperature on Efficiency ASKAP MkI Prototype PAF - MaxSNR Boresight Beam parkes_ \f_ Frequency (GHz) Assuming η = 0.8, implies T spill ~ 10 K MkI already achieving T sys = K, for GHz XX YY

27 ASKAP PAF MkII Key enhancement areas: RF over fibre Electronics packaging Mechanical packaging Cooling Control/monitoring Power supply Checkerboard performance The enhancements aim to: Reduce cost, weight, complexity and construction time by 50% Decrease maintenance time easier access/servicing Increase in performance of PAF

28 ASKAP PAF MkII (cont.) Software Defined Radio Frequency down conversion no longer required Direct sampling of three RF bands in excess of 300MHz BW ADC clock is only system clock central site distribution Next generation Kintex-7 FPGAs Lower cost and power per unit processed Faster IO (10Gbps data commsand 800MTps DDR3 memory) Next generation Multimode parallel optics Enables backplane less design (optical cross connect) Lowers data transport cost between beamformerand correlator Simpler data communications firmware System packaging Low cost PC COTS components case, power, cooling, etc.

29 ASKAP PAF Modelling Aperture-Plane Array T rec for Boresight Beam source: Hay 2011, unpublished

30 ASKAP PAFs Next Steps 2011 PAF on dish at Parkes PAF on dish at MRO Mk I PAFs operating on antennas at MRO ASKAP Design Enhancements Good T sys over full band Reduce complexity/cost/power/weight order 50% RF over fibre, direct sampling & Virtex 7 Build 6 Mk II PAFs 2013 Full rollout of electronics Early commissioning science Continue with Mk II deployment on all 36 dishes

31 Parkes: PAF prototype/science test-bed Develop standardised SKA-compliant PAF interface/ footprint together with SPO Deploy standardised interface/footprint version of ASKAP MkII system ~30 Beams: MHz, T sys < 55 K, high η B RFoF is vital for Parkes installation, hence no Mk I Deploy MkIII, IV PAF systems as developed for SKA Designed for SKA B1, B2: and GHz Possibly implement cryo for maximum performance Explore higher SKA frequency bands: B3, 4 and 5 Enable wide-fov science on Parkes with PAF prototypes as available

32 CSIRO Astronomy & Space Science Robert Braun Chief Scientist Phone: Robert.Braun@csiro.au Web: Thank you Contact Us Phone: or enquiries@csiro.au Web: