Science at Q-band Manchester 14-15 September 2009 APRICOT All Purpose Radio Imaging Cameras On Telescopes Peter Wilkinson U. Manchester Design studies & sub-system prototyping for future large-format Q-band FPA “cameras” on large telescopes 2) MIC + MMIC devices from within Europe. Science at Q-band Manchester 14-15 September 2009

EC Framework7 “RadioNet” Instrumention R&D APRICOT : Q-band camera subsystems + European MIC/MMICs (Caltech/JPL MMIC array spectrographs & NRAO FPA goals overlap with APRICOT) AMSTAR+ : mm/sub-mm cameras subsytems (SIS, MMIC) (W-band FPAs overlaps with APRICOT) (UNIBOARD: multi-purpose digital backends) Science at Q-band Manchester 14-15 September 2009

Some European Q-band telescopes Yebes-40m SRT 64-m Effelsberg-100m (new active 2ry mirror) Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 Science Strategy “Cameras” enable these telescopes to make new surveys in scientifically rich range 33-50 GHz – In “intermediate” gap between SKA and ALMA Follow-up with EVLA, VLBI, VSOP-2, ALMA Band 1 Continuum and spectroscopy: observations in different weather conditions Complement other mmsub-mm observations Complement CMBR observations e.g. Planck Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 APRICOT: Basics Operating range: 33-50 GHz spectrally rich + many continuum applications All Stokes parameters + spectroscopy at same time Continuum band split into (n x few GHz) sub-bands for atmospheric & spectral discrimination. Broad-band IF output selected from anywhere within overall band, sent to high-speed digital FTS (UNIBOARD) Science at Q-band Manchester 14-15 September 2009

Molecular Line Spectroscopy Star-forming regions & circumstellar envelopes Imaging plus modelling  temperature & density Many carbon-chain species in the 30-50 GHz band (HCnN n=3,5,7; CnH n=5,6; CnS n=1,3,5) diagnostic of cold dense quiescent gas Other species: SiO (shock tracer); OCS (sulphur sink) CH3CN (hot core species); SO (Zeeman sensitive) SiO masers in CSEs close to the star With large format cameras could survey complete clouds in one day Blind surveys in redshifted CO (1-0) Distances & mass estimates of dusty galaxies Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 Continuum Studies Surveys for discrete sources (in polarisation) Find new types of AGN e.g. youngest CSOs follow-up with mm-VLBI & VSOP-2 imaging follow-up of GLAST transients Provide net of calibration sources for EVLA and mm-VLBI Support of Planck and all high-sensitivity CMBR experiments Surveys for/of clusters of galaxies via the S-Z effect Surveys of diffuse Galactic emission (in polarisation) Synchrotron; free-free; anomalous dust; thermal dust Need to dissect out the contributions: for ISM astrophysics and CMBR polarised foregrounds In compact regions e.g. YSOs - diagnostics of dust agglomeration in protoplanetary disks Science at Q-band Manchester 14-15 September 2009

Scientific Synergy Surveys with radio cameras link these fields a wealth of astrophysics becomes accessible if we study both galactic and extragalactic foregrounds with precision for progress in cosmology must understand the unpolarized and polarized foregrounds with exquisite precision Surveys with radio cameras link these fields MAS Meeting Pasadena, 27 April 2005 Science at Q-band Manchester 14-15 September 2009

Relevant FPA experience Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 EMBA: 32 GHz (MPIfR) Dewar interior 7-beam horn array with different properties Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 FARADAY 18-26 GHz (IRA) 7 feed, hexagonal configuration with central feed 14 x 2 GHz IF outputs right and left polarization; Feeds and LNAs cooled at 20 K; Mechanical de-rotator to track the parallactic angle Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 OCRA 26-36 GHz (U. MAN) Single polarisation continuum 26-36 GHz Direct detection All-MMIC receiver based on WMAP/Planck- LFI design NGST InP MMICs Horns all cold – behind self-supporting 480mm vacuum window 26-36 GHz 16-beams Continuum (UMAN) Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 EXPERIENCE...... NGST MMIC performance: very good - ITAR produced great delays MMIC chips to “mass production” of LNAs  extraordinarily long Dewar: many devices, cables, wires, connectors  big, complicated Noise marker and LO distribution: simple in principle but complicated LNA power supply: complicated, huge amount of thin wires Weight: great Maintenance: maybe lots Science at Q-band Manchester 14-15 September 2009

Hence the need for major changes in approach… Science at Q-band Manchester 14-15 September 2009

WP1 Receiver Architecture MPIfR; IRA, UMAN, CAY, TCfA Architectures for highly integrated multi-pixel receivers Modular design with well-defined interfaces Design for mechanical and cryogenic stability Optimise layout for maintenance/fault-fixing Design of monitor, control and calibration systems Integration of direct detection and heterodyne systems LO generation and distribution Design, packaging and integration of RF, IF, LO systems Establish capability to batch-produce RF, IF modules Deliverables are mainly design study reports Science at Q-band Manchester 14-15 September 2009

WP2: passive components IRA; MPIfR, UMAN Highly integrated chain with OMT, hybrids, transmission sections etc Low-loss, low size/weight, low cost, ease of manufacture Standard waveguide technology too expensive Needs technology shift  Planar technology, microstrip transmission lines and filters etc Deliverables - design study reports - few pixels hardware comparing performance of conventional and “innovative” approaches (with WP1 and WP3) Science at Q-band Manchester 14-15 September 2009

WP3: MIC/MMIC development UMAN; IRA; MPIfR; CAY; URomeTV To develop and secure European supply of world-standard MMIC devices for astronomy To seek improved noise performance: TLNA stuck at 5-6 x Quantum Limit for >10 years: why? To explore/achieve increased levels of integration & multi-function capability within a MMIC circuit. Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 MIC/MMIC producers Fraunhofer Institute (IAF) Freiburg 100 & 50 nm GaAs mHEMT technology Multi-function MMICs Experimental 35nm processes Now interested in low-noise at cryo temps Link with AMSTAR+ U. Manchester 100nm InP HEMT technology innovation in materials and architecture for low-noise rapid response to new design inputs OMMIC company 70nm GaAs mHEMT technology Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 WP4: Device Testing CAY; UMAN; MPIfR, IRA; URomeTV Accurate measurement of noise temperature and gain fluctuation of devices at cryo temperatures not easy Results from well-respected labs often differ ! CAY have lots of experience in this arena from LNA work for Herschel (HIFI), ALMA, IRAM, ESOC etc Science at Q-band Manchester 14-15 September 2009

Synergy with “MMIC Array Spectrographs” Caltech/JPL: aims similar to APRICOT/AMSTAR+ Push for lowering InP pHEMT noise closer to quantum limit in collaboration with NGST Why don’t MICs and MMICs perform the same from wafer to wafer? Why don’t MMICs in modules perform as well as expected ? (QUIET experience) Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 WP5: Data handling TCfA: UMAN, IRA, MPIfR Develop and test algorithms using the full range of multi-pixel and multi-spectral data to reduce effects of 1/f noise and atmosphere without spatial switching, (“on the fly-mapping” – strongly affects receiver concept) Develop and test figures-of-merit to support queue- scheduling of the receiver in both continuum and spectroscopic modes Combine knowledge with other mm-wave users Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 Emerging Specification Npixels and configuration 25100 Limits from optics: SRT ~30 beams for 0.5db loss Configuration affects survey efficiency: hexagonal may not be best for beam-beam switching Tsys <50K RX temperature <25K + sky ~ 25K . Higher Tsys (>5 K) could be tolerated for larger Npix Total RF Bandwidth 33-50 GHz Waveguide band: Goal is 17 GHz BW to backend Which few GHz is least important? Polarisation type LCP/RCP or X/Y Needs detailed discussion Polarisation purity 30dB Set by science demands Hard to maintain 30 db over 46% BW with circular? Continuum channels per pixel 8 For atmospheric diagnosis and instant spectra. Critical requirement for the architecture Spectroscopic coverage 17 GHz instant >2 GHz RF bands Architecture possible to deliver all RF band, split in channels per pixel, to spectrometer with no tuning Gain stability /knee frequency ??? Acceptability? Depends on observation technique Rapid scan rates allow on-the-fly mapping major issue for WP5 simulations Spectroscopic channels per pixel 64k for each 2 GHz band Demand on backend to UNIBOARD Resolution ~30 kHz – science “would like” 15 kHz Science at Q-band Manchester 14-15 September 2009

Science at Q-band Manchester 14-15 September 2009 Advice requested Bandwidth goal is 17 GHz (46%) split into ~8 continuum bands - which end is scientifically more important if compromises needed? Receiver is simpler if the internal switching schemes are minimised/nil – challenge is observing with 1/f gain variations and weather – experience on antenna driving requirements ? Pixel calibration: - acceptable variation between pixels? Spectroscopy - is ~2 GHz instantaneous enough? - is spectral resolution of 15 kHz = 0.1km/sec within a 2 GHz band OK? - what is the specification on bandpass ripple within channels? Polarisation specifications: - linear or circular – any comments? - separation purity: 30 dB ?- maybe hard to maintain withm circular polarisation across a 46% BW) Science at Q-band Manchester 14-15 September 2009