Yebes Observatory BRAND EVN BROADBAND RECEIVER - A TECHNOLOGICAL CHALLENGE - Gino Tuccari on behalf of the BRAND team G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
WHAT IS A BRAND RECEIVER Max-Planck-Institut für Radioastronomie “Digital” VLBI -receiver for the EVN (and other) telescopes Frequency range: 1.5 - 15.5 GHz Direct sampling – no down-conversion Sampling by a single sampler chip Data transport from receiver to backend via optical fibers Will bypass IF limitations of legacy antennas Will allow multi-wavelength VLBI for astronomy Fringe-fitting over whole band necessary (RadioNet JRA RINGS) Will extend VGOS band G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
BRAND JRA IN RADIONET Max-Planck-Institut für Radioastronomie BRAND EVN is a Joint Research Activity (JRA) in H2020 Radionet Contract with the EU No: 730562 Budget sponsored by the EU: ~1.5 M € plus in-kind contributions by partners: MPIfR, INAF/Noto, OSO, UAH/IGN, ASTRON, VUC Project started: January 2017 Project ends: December 2020 Prototype BRAND receiver for Effelsberg prime focus Research for secondary focus feeds Suitability study for other EVN antennas G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
EVN FREQUENCIES Max-Planck-Institut für Radioastronomie G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
EVN FREQUENCIES VS. BRAND Max-Planck-Institut für Radioastronomie G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
THE BRAND TEAM Max-Planck-Institut für Radioastronomie W. Alef MPIfR Bonn, Project Manager, VLBI test observations Germany G. Tuccari INAF Noto & Project Engineer, BRAND architecture, HTSC filters, MPIfR Bonn backend design, firmware, secondary focus study J. Flygare, L. Pettersson OSO, Sweden Feed Horn, measurements of filter plus LNA J.A. López-Pérez, F. Tercero, IGN/UAH, Spain LNAs, RFI, measurements of filter plus LNA, analogue I. Malo, I. López-Fernández, polarisation conversion C. Diez C. Kasemann, M. Nalbach MPIfR Bonn, Dewar, frontend integration, integration in Effelsberg tel. Germany M. Wunderlich, S. MPIfR Bonn, Sampler & processing board layout, firmware, software, Dornbusch, A. Felke, H. Germany recording, correlation Rottmann J. Hargreaves, G. ASTRON, Digital polarisation conversion, software Schonderbeek, R. de Wilde Netherlands G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
BRAND PROJECT STRUCTURE Max-Planck-Institut für Radioastronomie Radionet board Gino Tuccari Walter Alef Project engineer Project manager Workpackge structure 6.1 Feasibility 6.2 Frontend 6.3 Backend 6.4 Software 6.5 Integration survey (UAH-IGN) Primary focus Sampler (INAF, Control Integration (all) • • • • feed (OSO) MPIfR) (MPIfR, INAF) Lab tests (all) • HTSC filters (INAF) • FPGA (INAF, MPIfR) Recording Telescope test • • • LNA (UAH-IGN) • Firmware (INAF, (MPIfR) (all) • Cryostat MPIfR, ASTRON) Correlation • Study of • &Integration Integration (MPIfR) secondary focus • (MPIfR) (INAF,MPIfR) feed G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
STATUS FEED HORN Max-Planck-Institut für Radioastronomie Feed horn designed by J. Flygare, M. Pantaleev, OSO Solution found for Effelsberg: QRFH feed with dielectric inset Antenna parameters: Opening angle 160 ° f/D = 0.3 Feed characteristics (over whole band): average aperture efficiency of 50% input reflection better than -10 dB Feed manufactured and measured Ongoing: Measure filter + amplifier G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
STATUS FEED HORN Max-Planck-Institut für Radioastronomie G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
FEED HORN: SEFD & EFFICIENCY Max-Planck-Institut für Radioastronomie G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
MANUFACTURED FEED HORN Max-Planck-Institut für Radioastronomie G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
STATUS: HTSC FILTERS Max-Planck-Institut für Radioastronomie High Temperature Superconductor Filters, desired: a high pass to cut below 1.5 GHz 2 notches for strongest RFI → (1.8 GHz, 2.2 GHz) A direction coupler for phase-cal & calibration Realized in 3 separate devices LNA + HTSC filters + coupler measured at Onsala and Yebes
STATUS: LNA Max-Planck-Institut für Radioastronomie Best solution for extreme bandwidth found: Balanced amplifier with 2 hybrids and 2 LNAs 0 20 Single LNA Bal. 2-14 GHz Single LNA -5 Bal. 1.5-15.5 GHz 7 st Input Return Loss (dB) Bal. 2-14 GHz Bal. 1.5-15.5 GHz 5 st Bal. 1.5-15.5 GHz 7 st 15 -10 Bal. 1.5-15.5 GHz 5 st -15 Noise (K) -20 10 -25 -30 5 -35 0 -40 0 2 4 6 8 10 12 14 16 18 0 2 4 6 8 10 12 14 16 18 Frequency (GHz) Frequency (GHz) G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
MEASUREMENTS OF FILTERS + LNA Max-Planck-Institut für Radioastronomie High noise above 11.5 GHz due to coupler G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
MEASUREMENTS OF FILTERS + LNA Max-Planck-Institut für Radioastronomie G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
STATUS: POLARIZATION Max-Planck-Institut für Radioastronomie Linear to circular polarization conversion can be achieved using 3dB/90º hybrid (same hybrid as for balanced LNA) Average noise penalty across the band < 2.5 Kelvin Yebes development for BRAND and VGOS LHCP H 3dB Feed 90º V RHCP Temp = 15K G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
DIGITAL FRONTEND Max-Planck-Institut für Radioastronomie Sampler can process 128 GSps (2 x 56 GSps or 4 x 28 GSps) Band formation of sampler output by FPGA Mode 1 Mode 2 FPGA Sampler (4 x 28 GSps) Sampler (2x56 GSps) 1.5 – 14.0 FPGA 1.5 – 15.5 To backend To backend 14.0 – 15.5 48 lanes 64 fibres FPGA 96 lanes 64 fibres FPGA 1.5 – 14.0 FPGA 1.5 – 15.5 14.0 – 15.5 FPGA G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
DIGITAL RECEIVER -CONT Max-Planck-Institut für Radioastronomie Mode 2 • Sampling on 4 ports with 28 GSps • Avoids extreme sampling clock in FPGAs • Requires splitting of analogue signal into • 1.5 – 14.0 GHz • 14.0 -15.5 GHz • Very good filters are required to minimize aliasing effects at 14 GHz Mode 1 Hardware can be changed to with moderate effort • 1.5 – 15.5 GHz • No filters are required to minimize aliasing effects at 14 GHz G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
BRAND BLOCK DIAGRAM Max-Planck-Institut für Radioastronomie frontend backend G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
SIGNAL PROCESSING IN RECEIVER Max-Planck-Institut für Radioastronomie • Receiver output: digital signal via optical fiber • Strong shielding is required to avoid ‚self - inflicted‘ RFI (> 120 dB) • Good temperature management is needed to get rid of the resulting heat G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
STATUS: DIGITAL FRONTEND Max-Planck-Institut für Radioastronomie The samplers were procured and tested successfully Purchase of an evaluation sampler board Used for firmware development The final design of the sampling/processing board has started Will handle 2 polarizations and full bandwidth 1 sampler w. 4 inputs @14GHz, 4 Xilinx Kintec Ultrascale FPGAs 2x 0 – 14GHz, 2x 14 – 15.5 GHz in 2 nd Nyquist zone 2x 0 – 15.5GHz in 1 st Nyquist zone PCB will work in the microwave regime: Input is ~900 Gb/s G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
BLOCK DIAGRAM DIGITAL FRONTEND “ DIFREND ” Max-Planck-Institut für Radioastronomie G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
DIFREND : DIGITAL FRONT-END BOARD “ COREAGLE ” Max-Planck-Institut für Radioastronomie Input: 4 x 14 GHz or 2 x 28 GHz Sampling: (today) 8-bit @28/56 GHz 1 Tbps to FPGAs (Preliminary 8-bit @96/128 GHz 3.192/4.096 Tbps to FPGAs) Output from FPGAs: 64 x 10 Gbps to accomplish DBBC3 digital input G. Tuccari, "RadioNet Workshop: Future Trends in Radio Astronomy Instrumentation, September 21-22 2020
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