SKA Phased Array Feed Advanced Instrumentation Program SKA Engineering Meeting 1 6 October 2016 PAF AIP Consortium
Outline PAF Advanced Instrumentation Program Ø Members Ø Overview Ø Scope SKA PAF Dish Consortium Engagement Ongoing SKA Related PAF Developments AIP Activities Challenges Next Steps
PAF AIP - Members Consortium Foundation Members Ø NRC (Canada) Ø ASTRON (The Netherlands) Ø JBCO (UK) Ø INAF (Italy) Ø CSIRO (Australia) - Lead Potential Additional Members Ø JLRAT (China) Ø MPIfR (Germany)
PAF AIP - Overview SKA Organisation has agreed to set up a PAF AIP The PAF AIP aims to continue existing SKA PAF development by building on PAF work already investigating newly emerging technologies that promise to increase the performance of PAF systems Initially the AIP will focus on developing metrics and requirements to support future developments of PAFs for the SKA
PAF AIP - Overview Initial AIP Plan to SKA Board November 2016 The AIP will: Ø Run for the remainder of SKA Preconstruction Late 2018 Ø Deliver a System Requirements Review (SRR) and Conceptual Design Review (CoDR) Ø Be a precursor to a PAF development program during SKA Construction (ODP)
PAF AIP Scope of Technical Work Primary Room Temperature PAFs at low and/or high frequencies Cyrogenic PAFs at low and/or high frequencies Digitisation Signal Processing / Beamforming Calibration Subsequent Manufacturability & maintainability Weight reduction Cost (manufacture & operating) Power consumption
PAF Dish Consortium Engagement SKA SKA Dish common optical configuration defined and dish design well developed. Ø 15m Offset Gregorian Ø 5m sub-reflector (oversized) Ø Shaped reflector with 58 openning angle Ensure SKA1_MID antenna design is PAF compatible Ø SKA SKA Feed Indexer design and structure interfaces Ø SKA_Survey Band 2 PAF replaces SKA SPF Band 1 Ø SKA_Survey Band 3 PAF replaces SKA SPF Band 3, 4, 5. Basic system architecture defined PAF ICD Compatibility with SKA_Mid antennas
Precursor PAF Development NRC Advanced Focal Array Demonstrator (AFAD) 0.7 1.5GHz (SKA - Band 2) Cryogenic cooling (CryoPAF4) 2.8 5.18 GHz (SKA - Band 4) Credit: B. Veidt, NRC Canada ASTRON APERTIF (SKA Band 2) CSIRO JBO, ASTRON, INAF PHAROS (SKA Band 4,5) Mk. II Chequerboard array (SKA Band 2) Mk. III Rocket array (SKA Band 2)
PAF Development - NRC AFAD Frequency Range 0.7-1.5GHz (SKA Band 2) Uses low-loss element design Ø Thick Vivaldi elements (5mm) Ø LNA at feed point Currently assembling an all-cmos 96 element array Ø Digital beamforming Ø Initial aperture array tests using NRC Hot/Cold Test Facility by end of 2016 Ø Will be tested on DVA-1 with offset Gregorian optics
PAF Development - NRC AFAD Recent tests with CMOS LNAs in 9 central elements gave good results Ø Aperture array test using sky as cold load Ø T receiver ~ 20-30K Ø Analog beamformer
PAF Development - NRC CryoPAF4 2.80 5.18 GHz (SKA Band 4) Cryogenic operation (16 K, 70 K stages) 48 cm diameter cryostat Composite laminate radome vacuum barrier Multi-layered RF transparent IR shields Metal dual-polarized Vivaldi array (16 K physical) Ø 31 cm diameter, 2.8 cm square grid spacing Ø 96 active elements, 44 passive = 140 total Ø 48 linear x, 48 linear y Low noise amplifier (16 K physical, 3.5 K noise temperature) Sampling and 18 beam dual-polarization frequency domain beamformer Estimated T receiver = 11 K
PAF Development - NRC CryoPAF4 Status (Q2 2016) Design: Ø All in-house design Ø Composite radome NRC Penticton Ø Vivaldi machining at NRC Victoria Ø RF push-on GPO type connector between Vivaldi and LNA Ø 3-stage, 40 db LNA design NRC Victoria Ø Cryogenic/thermal dewar design, finite element analysis (FEA) Ø Digital Beamformer (frequency domain) for production Prototype ~2017 Full Scale ~2018-19 Ø SKA Construction/ODP
PAF Development JBO, ASTRON, INAF PHAROS Ø Cryogenic receiver Ø MMIC 4-8GHz LNA (ASTRON) Ø Analog MMIC based beamformer Phased Array Feed Development Update Mark Bowen Page 19
PAF Development - ASTRON APERTIF - Status Ø All hardware in place at the 12 dishes (frontends, beamformers, etc). Technical commissioning in full swing Ø Final correlator installed in HF-cabin (at Westerbork) Ø Finishing correlator firmware Ø Currently able to correlate 9 dishes Ø Science commissioning progressing Ø Online calibration interval > 1 hour system stable
PAF Development - ASTRON APERTIF - Future Work APERTIF Busy week (27 Sep 6 Oct) Ø Goal: have a working system, that can be controlled by scripts that astronomers (and observers) can execute. Ø Milestone: Full Field of View End of the year Ø Continue technical commissioning (end of 2016) Ø Continue science commissioning (2016-2017) ØSoftware elements in place to be able to start surveys (end 2016) Ø Longer tests online calibration (late 2016)
PAF Development - CSIRO Mk. I - Boolardy Engineering Test Array Ø 6 antennas - Mk. I Chequerboard PAFs Ø Very useful commissioning practice platform Ø Decommissioned February 2016 MK. II - ASKAP Design Enhancement Ø 12 antennas currently operational Ø Mid scale production pathfinder Ø Commissioning lessons continue
PAF Development - CSIRO Mk. III - Element and LNA Design Element based on a conical solid of revolution Edge elements designed to reduce the effect of the edge discontinuity Feed line loss minimised Balanced LNA Differential impedance 180Ω Commercial HEMT LNA TriQuint TQP3M939 & TQP3M9040 5 x 4 array constructed as proof-ofconcept T sys Reduction of T LNA = 5K 7K over ASKAP Mk II LNA achieved
PAF Development CSIRO and MPIfR Parkes granted pathfinder status as of April MPIfR Bonn PAF on Parkes Ø Undergoing characterisation testing Ø To Effelsberg in October/November Cryogenic PAF being considered for Parkes Rocket element - Parkes and SKA Ø Prototype measured Photo credits: J Sarkissian Uniform weights aperture array mode measurement
PAF2016 Workshop Cagliari http://paf2016.oa-cagliari.inaf.it/
Performance Room Temperature PAFs Measurements calibrated using ASKAP (Mk. II) reference array. Gaps in the measurements are caused by RFI.
PAF AIP - Challenges System cost Signal processing Improving manufacturability Improving noise performance Competitive with traditional feed horn based systems Sky de-rotation Mechanical, electronic, software Beamforming algorithm development Calibration
AIP Next Steps Establish the framework for the PAF AIP to present to the SKA board Engage a PAF AIP Consortium Board Engage a PAF Program Scientist Engage a PAF Program System Engineer Develop a set of requirements. Develop metrics to assess PAFs against requirements. Investigate a common test facility
AIP Further Considerations Access to an SKA Engineering Array Ø 3 4 Antennas (minimum) Ø Support facilities Ø Integration centres Relationships with consortia Dish, SaDT, CSP, TM Status during ODP/construction phase Roll-out and AIV
Acknowledgements Mark Bowen Lisa Locke Bruce Veidt Lei Liu Raymond van den Brink Doug Hayman
Thank You CSIRO Astronomy and Space Science Steve Barker +61 2 9372 4523 Steve.Barker@csiro.au www.csiro.au SKA Organisation Mark Bowen +44 161 306 9610 m.bowen@skatelescope.org www.skatelescope.org