| 1. |
- Barkhof, J., et al.
(författare)
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ALMA Band 2 Receiver Automated Test System
- 2022
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Ingår i: 32nd International Symposium of Space Terahertz Technology, ISSTT 2022.
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Konferensbidrag (refereegranskat)abstract
- As part of the ALMA Band 2 project, an automated test system was developed to fully qualify state-of-the-art Band 2 receivers, based on heritage of the Band 9 and Band 5 productions. The RF range of this receiver is 67 - 116 GHz, with a goal IF band of 4-18 GHz. Each receiver will undergo a thorough acceptance testing to verify its operation and performance prior to delivery. The core of the test system are a single-cartridge test cryostat, a dual-channel intermediate frequency signal processor, a vector near-field test system, and script-based measurement and control software that enables automated testing. We present details of the test system and measurement results of the first Band 2 receivers.
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| 2. |
- Belitsky, Victor, 1955, et al.
(författare)
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ALMA Band 2 Cold Cartridge Assembly Design
- 2022
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Ingår i: 32nd International Symposium of Space Terahertz Technology, ISSTT 2022.
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Konferensbidrag (refereegranskat)abstract
- As part of the ALMA development, we present the design of the ALMA Band 2 Cold Cartridge Assembly (CCA). The Band 2 is the last band that completes the suit of the 10 receiver channels of ALMA. The originally planned ALMA Band 2 receiver cartridge should cover the RF band of 67 - -90 GHz. The recent progress in technology, optics, OMT design and mm-wave amplifiers, however allowed to implement receiver that has an extended RF band up to 116 GHz. Furthermore, the Band 2 receiver pursues 2SB layout and provides 4-18 GHz IF band for two sidebands in a dual-polarization configuration. Here, we describe the design of the Band 2 CCA that includes optics, amplifier assembly, internal RF transport, mechanics and cryogenics. The downconverter part and performances are described elsewhere.
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| 3. |
- Lapkin, Igor, 1963, et al.
(författare)
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Vacuum-Seal Waveguide Feedthrough for Extended W-Band 67-116 GHz
- 2023
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Ingår i: IEEE Journal of Microwaves. - 2692-8388. ; 3:3, s. 1014-1018
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Tidskriftsartikel (refereegranskat)abstract
- This article describes the design and performance of a vacuum-seal waveguide feedthrough with ultrawide RF band 67-116 GHz. We describe first the initial drivers behind the chosen design, then we present the results of the numerical simulations and optimization and provide thereafter the results of the RF and vacuum tests of the fabricated devices. The demonstrated RF performance is very close to the one expected from the simulation with an insertion loss less than 0.3 dB and a return loss better than 20 dB. Simultaneously, the feedthrough shows excellent vacuum isolation, Helium gas leak rate of < 2x10(-8) mbar center dot L/s is demonstrated, which allows using such a device in various space and ground applications.
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| 4. |
- Meledin, Denis, 1974, et al.
(författare)
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SEPIA345: A 345 GHz dual polarization heterodyne receiver channel for SEPIA at the APEX telescope
- 2022
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 668
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Tidskriftsartikel (refereegranskat)abstract
- Context. We describe the new SEPIA345 heterodyne receiver channel installed at the Atacama Pathfinder EXperiment (APEX) telescope, including details of its configuration, characteristics, and test results on sky. SEPIA345 is designed and built to be a part of the Swedish ESO PI Instrument for the APEX telescope (SEPIA). This new receiver channel is suitable for very high-resolution spectroscopy and covers the frequency range 272- 376 GHz. It utilizes a dual polarization sideband separating (2SB) receiver architecture, employing superconductor-isolator-superconductor mixers (SIS), and provides an intermediate frequency (IF) band of 4- 12 GHz for each sideband and polarization, thus covering a total instantaneous IF bandwidth of 4 ÃÂ - 8 = 32 GHz. Aims. This paper provides a description of the new receiver in terms of its hardware design, performance, and commissioning results. Methods. The methods of design, construction, and testing of the new receiver are presented. Results. The achieved receiver performance in terms of noise temperature, sideband rejection, stability, and other parameters are described. Conclusions. SEPIA345 is a commissioned APEX facility instrument with state-of-the-art wideband IF performance. It has been available on the APEX telescope for science observations since July 2021.
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| 5. |
- Meledin, Denis, 1974, et al.
(författare)
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SEPIA345: a dual polarization 2SB cartridge receiver for APEX telescope: Design and Performance
- 2023
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Ingår i: Proceedings of the 32nd IEEE International Symposium on Space THz Technology.
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Konferensbidrag (refereegranskat)abstract
- A new receiver channel covering the 271-377 GHz frequency band has been installed into the SEPIA receiver at the APEX telescope. The receiver channel was designed and built in an ALMA-compatible cartridge layout. The receiver has a dual polarization layout with OMT and employs 2SB SIS mixers featuring an extended 4-12 GHz IF band, providing 32 GHz instantaneous IF bandwidth for two polarizations and two sidebands.
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| 6. |
- Meledin, Denis, 1974, et al.
(författare)
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SEPIA345: a dual polarization 2SB cartridge receiver for APEX telescope: Design and Performance
- 2022
-
Ingår i: 32nd International Symposium of Space Terahertz Technology, ISSTT 2022.
-
Konferensbidrag (refereegranskat)abstract
- A new receiver channel covering the 271-377 GHz frequency band has been installed into the SEPIA receiver at the APEX telescope. The receiver channel was designed and built in an ALMA-compatible cartridge layout. The receiver has a dual polarization layout with OMT and employs 2SB SIS mixers featuring an extended 4-12 GHz IF band, providing 32 GHz instantaneous IF bandwidth for two polarizations and two sidebands.
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| 7. |
- Montofre, Daniel, 1989, et al.
(författare)
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A Broad-Band Dual-Polarization All-Metal Dichroic Filter for Cryogenic Applications in Sub-THz Range
- 2024
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Ingår i: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we report on the design and characterization of an all-metal, wideband single-layer dichroic filter operating at non-normal beam incidence. The dichroic filter consists of a perforated metal plate with an angular offset of the perforated channels equal to the beam incidence angle onto the dichroic surface. The fabricated filter is characterized using an especially designed quasi-optical test system. The filter demonstrates 96% transmission of the incoming electromagnetic radiation averaged in the signal band about 37-50 GHz for both polarizations while simultaneously achieving a rejection better than 20 dB for frequencies lower than 26 GHz at the designed beam incidence of 13 degrees. The cross-polarization level for each polarization is better than 30 dB in the passband. The experimental results of the transmission measurements are in very good agreement with electromagnetic simulations confirming the feasibility and benefits of our proposed design concept even at THz frequencies. The simulations of the dichroic scaled version demonstrate that, for instance, it can be employed in the Event Horizon Telescope project, where the 230 GHz and the 345 GHz receiver channels could be operating simultaneously.
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| 8. |
- Montofre, Daniel, 1989, et al.
(författare)
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A broadband and dual-polarization single-layer dichroic filter for applications in Sub-THz range
- 2022
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Ingår i: 32nd International Symposium of Space Terahertz Technology, ISSTT 2022.
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Konferensbidrag (refereegranskat)abstract
- In this work we report the design of a single-layer all-metall dichroic filter with an improved spectral response at non-normal beam incidence and nearly equal performance for both polarizations. The dichroic is intended to be employed for dual-frequency receivers. Since the dichroic is produced purely from metal it facilitates its use at cryogenic temperatures. Therefore, the contribution to the system noise is minimized. The dichroic design concept demonstrated a measured transmission of electromagnetic radiation of 85-90% for both polarizations in the range of 35-50 GHz (37% fractional bandwidth). The measurements were performed at room temperature. The spectral properties of the dichroic have been optimized by modeling in 3D FEM simulation software.
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| 9. |
- Yagoubov, P., et al.
(författare)
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Wideband 67-116 GHz receiver development for ALMA Band 2
- 2020
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 634
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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