Issue |
A&A
Volume 634, February 2020
|
|
---|---|---|
Article Number | A46 | |
Number of page(s) | 22 | |
Section | Astronomical instrumentation | |
DOI | https://doi.org/10.1051/0004-6361/201936777 | |
Published online | 04 February 2020 |
Wideband 67−116 GHz receiver development for ALMA Band 2
1
European Southern Observatory (ESO), Garching, Germany
e-mail: pyagoubo@eso.org, amroczko@eso.org
2
Group for Advanced Receiver Development (GARD), Chalmers University of Technology, Gothenburg, Sweden
3
Jodrell Bank Centre for Astrophysics, School of Physics & Astronomy, The University of Manchester (UoM), Manchester, UK
4
School of Electrical & Electronic Engineering, The University of Manchester (UoM), Manchester, UK
5
Istituto Nazionale di Astrofisica (INAF/OAS), Bologna, Italy
6
Observatorio de Yebes, Guadalajara, Spain
7
National Astronomical Observatory of Japan (NAOJ), Mitaka, Tokyo, Japan
8
Universidad de Chile (UdC), Santiago, Chile
9
Istituto Nazionale di Astrofisica (INAF/OAA), Arcetri, Italy
10
Dipartimento di Fisica, Universita degli Studi di Milano, Milano, Italy
11
Radiometer Physics GmbH (RPG), Meckenheim, Germany
12
University of Michigan, Department of Physics, Ann Arbor, MI, USA
13
Academia Sinica, Institute of Astronomy & Astrophysics (ASIAA), Taipei, Taiwan
14
Institute of Applied Physics, University of Bern, Bern, Switzerland
15
Istituto Nazionale di Astrofisica/Istituto di Radioastronomia (INAF/IRA), Bologna, Italy
16
Low Noise Factory (LNF), Gothenburg, Sweden
Received:
24
September
2019
Accepted:
20
December
2019
Context. The Atacama Large Millimeter/submillimeter Array (ALMA) has been in operation since 2011, but it has not yet been populated with the full suite of its planned frequency bands. In particular, ALMA Band 2 (67−90 GHz) is the final band in the original ALMA band definition to be approved for production.
Aims. We aim to produce a wideband, tuneable, sideband-separating receiver with 28 GHz of instantaneous bandwidth per polarisation operating in the sky frequency range of 67−116 GHz. Our design anticipates new ALMA requirements following the recommendations of the 2030 ALMA Development Roadmap.
Methods. The cryogenic cartridge is designed to be compatible with the ALMA Band 2 cartridge slot, where the coldest components – the feedhorns, orthomode transducers, and cryogenic low noise amplifiers – operate at a temperature of 15 K. We use multiple simulation methods and tools to optimise our designs for both the passive optics and the active components. The cryogenic cartridge is interfaced with a room-temperature (warm) cartridge hosting the local oscillator and the downconverter module. This warm cartridge is largely based on GaAs semiconductor technology and is optimised to match the cryogenic receiver bandwidth with the required instantaneous local oscillator frequency tuning range.
Results. Our collaboration has resulted in the design, fabrication, and testing of multiple technical solutions for each of the receiver components, producing a state-of-the-art receiver covering the full ALMA Band 2 and 3 atmospheric window. The receiver is suitable for deployment on ALMA in the coming years and it is capable of dual-polarisation, sideband-separating observations in intermediate frequency bands spanning 4−18 GHz for a total of 28 GHz on-sky bandwidth per polarisation channel.
Conclusions. We conclude that the 67−116 GHz wideband implementation for ALMA Band 2 is now feasible and that this receiver provides a compelling instrumental upgrade for ALMA that will enhance observational capabilities and scientific reach.
Key words: instrumentation: interferometers
© ESO 2020
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.