1. AA-mid demonstrator Dion Kant AAVP 2010 8 – 10 December 2010, Cambridge, UK.

2. AA-mid 2 - GWK, 2010/12/10 AAVP 2010 Outline Project target Description of Work Project partnerships Current activities Evaluation results Conclusion

3. AA-mid 3 - GWK, 2010/12/10 AAVP 2010 AA-mid (draft) key requirements Physical collecting area~2000 m^2 Number of stations10 to 15 PolarisationDual polarisation Frequency range400 – 1450 MHz ArchitectureBased on EMBRACE T_sys50K Target Dynamic range @ ADC42 dB Instantaneous bandwidth~250 MHz Number of independent FoVs2 HPBW (FoV)16 degrees @ 1 GHz Station output bandwidth500 MHz Requirements may still be adapted

4. AA-mid 4 - GWK, 2010/12/10 AAVP 2010 AA-mid time line, phases and Full project (~2000 m^2 AA) not funded today AAVS1 = first phase Funding for design phase within AAVS1 –2010 to 2013 –Delivers design + small number of front end proto types –Use EMBRACE evaluation as input for design –Use EMBRACE platform as test-bed for new tile developments –New design based on EMBRACE Site selection will be decided on later First testing will be performed at current EMBRACE stations Second stage testing: Use Portugal site (SKA like environment) Second phase (AAVS2) (beyond 2013) full roll-out AA-mid demonstrator

5. AA-mid 5 - GWK, 2010/12/10 AAVP 2010 Design approach Base new design on EMBRACE architecture and other demonstrators Incremental approach –Level 1 topics (should) –Level 2 topics (may) Main enhancements are (level 1 topics): –Introduce dual polarisation signal processing –Reduce power consumption per signal path –Improve tile control system –Reduce system noise –Second generation beam former chip (4-bit phase control) –Improve mechanical design, this includes housing & radome –Improve design for manufacturability

6. AA-mid 6 - GWK, 2010/12/10 AAVP 2010 Design approach level 2 topics Investigate LNA above ground plane (integrated on feed board). Main goal is to be able to use FR4 for feed board (element cost reduction) Investigate balanced LNA approach Improve station processing bandwidth –Input bandwidth (250 MHz per channel) –Output bandwidth >2x250 MHz –As a fall back current EMBRACE processing hardware will be used Investigate non-continues Unit/substation approach; Obtain better EM model of tile to predict radiation pattern including polarisation behavior. ….

7. AA-mid 7 - GWK, 2010/12/10 AAVP 2010 7 XX “tiles” in a substation. Every substation slightly tilted. Substation closed by EPS wall en top. Passive cooling by ground connection through poles. SKA station formed by multiple substations. Walkable spaces between substations. 56m diameter 288.000 antenna elements Non-continues substations

8. AA-mid 8 - GWK, 2010/12/10 AAVP 2010 Design approach level 2 topics Topics to be solved : Need software development partnership Need correlator suitable for 15x2x1GS/s inputs … Can survive with current EMBRACE system in first phase of the project

9. AA-mid 9 - GWK, 2010/12/10 AAVP 2010 Project partnerships Established members: –OPAR, France: Part of system design, beam former chip design, EMBRACE evaluation; –ASTRON, the Netherlands: Part of system design, focus on level 1 front-end topics, industrialisation and EMBRACE evaluation –… Members (becoming established): –Italy, INAF: Possible topics: Receiver, LO system, … –UK Several Institutes: Antenna design alternatives including electronic integration and testing, Digital processing, … –Germany, MPIfR: Signal distribution and multiplexing, digital processing; –Portugal, Preparation for Portugal station roll out and site development –France, AD converter including poly phase filter bank integration –…

10. AA-mid 10 - GWK, 2010/12/10 AAVP 2010 Current Activities and Progress First AAmid proto type tile underway Octa boards Connection boards Center board Aluminum ground plane

11. AA-mid 11 - GWK, 2010/12/10 AAVP 2010 Current Activities and Progress First AAmid proto type tile underway Bottom view Octa concept

12. AA-mid 12 - GWK, 2010/12/10 AAVP 2010 AAmid Octa Concept; 3D bottom view Current Activities and Progress

13. AA-mid 13 - GWK, 2010/12/10 AAVP 2010 Improved element mechanics SKA Station Design Multiple vivaldi antennas in one sheet LNA close to pick-up point Plastic support to keep tops in place

14. AA-mid 14 - GWK, 2010/12/10 AAVP 2010 Aluminum Large Plates to decrease assembly time SKA Station Design Metal-Metal joining by clinching Also expandable (connectable) in other direction

15. AA-mid 15 - GWK, 2010/12/10 AAVP 2010 15 XX “tiles” in a substation. Every substation slightly tilted. Substation closed by EPS wall en top. Passive cooling by ground connection through poles. SKA station formed by multiple substations. Walkable spaces between substations. 56m diameter 288.000 antenna elements EM analysis of non-continues substations

16. AA-mid 16 - GWK, 2010/12/10 AAVP 2010 EM analysis of non-continues substations Vacuum formed “tile” bottom for six modules (approx. 1.5 x 2m) Placement in field by forklift or crane, like LOFAR HBA.

17. AA-mid 17 - GWK, 2010/12/10 AAVP 2010 Small tile: Simulate and measure

18. AA-mid 18 - GWK, 2010/12/10 AAVP 2010 Good resemblance model and measurements 1 = Edge 3 = Central Active reflection coefficients

19. AA-mid 19 - GWK, 2010/12/10 AAVP 2010 Good resemblance model and measurements Measured and simulated phases

20. AA-mid 20 - GWK, 2010/12/10 AAVP 2010 Current Activities and Progress EMBRACE Evaluation and test-bed development

21. AA-mid 21 - GWK, 2010/12/10 AAVP 2010 Status Nançay Station ~ 62 m 2 area 56 Tiles 4032 Vivaldi elements (single linear polarisation) Currently 48 tiles cabled up end-to-end Grouped into tilesets of 4 tiles 64 tiles to be installed by end 2010 Ultimately, 80 tiles in early 2011 Current Activities and Progress

22. AA-mid 22 - GWK, 2010/12/10 AAVP 2010 Status Westerbork Station 64 Tiles, (~70 m^2) 25 Tiles online in a 3x3 and 4x4 array configuration Ultimately 144 Tiles (160 m^2) in 2011 Current Activities and Progress

23. AA-mid 23 - GWK, 2010/12/10 AAVP 2010 Digital beam former details

24. AA-mid 24 - GWK, 2010/12/10 AAVP 2010 Modified architecture to more generic one Full data rate can be exploited: 2x62 Ebeamlets per CDO output; e.g. two beams of 12 MHz each Digital beam former software less complex (can use Matrix formalism now) Increased update rate digital beam weights

25. AA-mid 25 - GWK, 2010/12/10 AAVP 2010 EMBRACE station experiment objectives and results Detection of GPS satellite signals Scanned Beam Pattern on Afristar Redundant base line experiments on Afristar Solar Fringes and system noise verification Fringes of Cas A and Cygnus RECENT RESULT: Detection of pulsar Current Activities and Progress Simultaneous detection of two pulsars within one FoV Simultaneous detection of two widely separated pulsars using independent FoVs Detection of HI Simultaneous detection of HI and pulsars Beam swapping with beams on Cas A and Cygnus Correlate with WSRT dish RECENT RESULT: Detection of pulsar Plan

26. AA-mid 26 - GWK, 2010/12/10 AAVP 2010 Drift scan of GPS satellite Strong carrier at 1227MHz Subband statistics Pointing offset between tilesets

27. AA-mid 27 - GWK, 2010/12/10 AAVP 2010 Early highlights: solar fringes Interferometric measurement with 10 tiles two E-W ULAs frequency: 1179 MHz integration: 10 s bandwidth: 195 kHz Initial performance est. A/T = 4.7·10 -3 (to sun) Tsys = 103 – 117 K (to zenith)

28. AA-mid 28 - GWK, 2010/12/10 AAVP 2010 Early highlights: instrument quality Redundant baselines produce redundant visibilities

29. Scanned Tile Beam pattern measured on Afristar satellite ModelMeasurement

30. AA-mid 30 - GWK, 2010/12/10 AAVP 2010 Fringes of Cas A! Experimental settings 3x3 array 1254 MHz 30 s integration 195 kHz bandwidth Initial conclusions Confirms A/T Correlation offsets

31. AA-mid 31 - GWK, 2010/12/10 AAVP 2010 Pulsar detection Setup details

32. AA-mid 32 - GWK, 2010/12/10 AAVP 2010 EMBRACE first pulsar result

33. AA-mid 33 - GWK, 2010/12/10 AAVP 2010 Conclusion AA-mid is ramping up EMBRACE Pulsar Detection demonstrates first L- band AA detection ever! It demonstrates: Complete data path and processing is under control Hierarchical beam forming is working and much more to come Thank you