| 1. |
- Marouf Rashid, Hawal, 1982, et al.
(författare)
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Compact wideband passive and active component chips for radio astronomy instrumentation
- 2019
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Ingår i: ISSTT 2019 - 30th International Symposium on Space Terahertz Technology, Proceedings Book. ; , s. 50-56
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Konferensbidrag (refereegranskat)abstract
- In the 2SB receivers, the rejection ratio is determined among other factors by the performance of the quadrature hybrids. We have developed and fine‐tuned components that intended to be used in the IF chain and meet the requirements for new generation of compact wideband 2SB receivers. We present here the design and characterization of three multi‐section compact wideband 3 dB quadrature couplers (coupled line coupler – Lange coupler–coupled line coupler). Specifically, the miniaturized 3‐section hybrid chip made using thin‐film technology utilizes gold plated transmission lines and air bridges to connect the fingers of the Lange coupler (middle section The hybrids were designed to have the amplitude and phase imbalance better than 0.6 dB and ±3° respectively over a 3.5-12.5 GHz and 4-16 GHz frequency bands. Experimental verification of the assembly at 293 K and 4 K shows very good agreement between the measurements and simulations. Additionally, we demonstrate the suitability of the miniature hybrid chips, by implementing them in a balanced amplifier designed using a modular approach, which demonstrated promising results.
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| 2. |
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| 3. |
- 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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| 4. |
- Belitsky, Victor, 1955, et al.
(författare)
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Prototype ALMA Band 5 Cartridge:Design and Performance
- 2009
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Ingår i: Proceedings of the 20TH INTERNATIONAL SYMPOSIUM ON SPACE TERAHERTZ TECHNOLOGY, Charlottesville, VA, USA, April 20-22, 2009, s. 2-5.
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Konferensbidrag (refereegranskat)abstract
- The Atacama Large Millimeter/submillimeterArray (ALMA), an international astronomy facility, is apartnership of East Asia, Europe and North America incooperation with the Republic of Chile and aims to build aninterferometer radio telescope consisting of more than 60antennas. The instrument is under construction at the Llano deChajnantor, about 50 km east of San Pedro de Atacama, Chile.This work presents a part of ALMA frontend, the development,design and performance of one of the frequency channels of theALMA receiver, the Band 5 prototype cartridge for 163 – 211GHz frequency band.
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| 5. |
- Belitsky, Victor, 1955, et al.
(författare)
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Terahertz Instrumentation For Radio Astronomy
- 2009
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Ingår i: International Symposium on Terahertz Science and Technology between Japan and Sweden. ; , s. 28-29
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Radio Astronomy was always a frontrunner in the demand on terahertz technology. Millimetre and sub-millimetre wave receivers operate at ground-based observatories for more than 20 years with real Terahertz instruments making its way to ground-based [1] and space-based observatories, e.g., Herschel HIFI, during last years.In this talk, we will look at the key requirements to the radio astronomy and environmental science terahertz receivers using heterodyne technology. The most promising and established technologies for high-resolution spectroscopy instrumentation will be discussed. Using results of the Group for Advanced Receiver Development for Onsala Space Observatory 20 m telescope, for Atacama Pathfinder Experiment (APEX) telescope and ALMA Project Band 5, we will illustrate the trends and achievements in the terahertz instrumentation for radio astronomy.
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| 6. |
- Belitsky, Victor, 1955, et al.
(författare)
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Towards Multi-Pixel Heterodyne Terahertz Receivers
- 2011
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Ingår i: Proceedings of the 22nd International Symposium on Space Terahertz Technology, Tucson, AZ, USA, April 26-28, 2011. ; , s. 1-3
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Konferensbidrag (refereegranskat)abstract
- Terahertz multi-pixel heterodyne receivers introduce multiple challenges for their implementation, mostly due to the extremely small dimensions of all components and even smaller tolerances in terms of alignment, linear dimensions and waveguide component surface quality. In this manuscript, we present a concept of terahertz multi-pixel heterodyne receiver employing optical layout using polarization split between the LO and RF. The frontend is based on a waveguide balanced HEB mixer for the frequency band 1.6 – 2.0 THz. The balanced HEB mixer follows the layout of earlier demonstrated APEX T2 mixer. However for the mixer presented here, we implemented splitblock layout offering minimized lengths of all waveguides and thus reducing the associated RF loss. The micromachining methods employed for producing the mixer housing and the HEB mixer chip are very suitable for producing multiple structures and hence are in-line with requirements of multi-pixel receiver technology. The demonstrated relatively simple mounting of the mixer chip with self-aligning should greatly facilitate the integration of such multi-channel receiver.
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| 7. |
- Billade, Bhushan, 1982, et al.
(författare)
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Performance of the first ALMA Band 5 production cartridge
- 2011
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Ingår i: Proceedings of the 22nd International Symposium on Space Terahertz Technology, April 26-28th, 2011 - Tucson, Arizona, USA. ; , s. 56-56
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Konferensbidrag (refereegranskat)abstract
- We present performance of the first ALMA Band 5 production cartridge, covering RF frequencies from 163 GHz to 211 GHz. ALMA Band 5 is a dual polarization, sideband separation (2SB) receiver based on all Niobium (Nb) SuperconductorInsulator-Superconductor (SIS) tunnel junction mixer, providing 16 GHz of instantaneous RF bandwidth for the astronomy observations. The 2SB mixer for each polarization employs a quadrature layout. The sideband separation occurs at the output of the IF hybrid that has integrated bias-T for biasing the mixers, and is produced using superconducting thin film technology. Experimental verification of the Band 5 cold cartridge performed together with warm cartridge assembly, confirms the system noise temperature below 45 K, less than five quantum noise (5 hf/k) over most of the RF band, which is to our knowledge, the best results at these frequencies. The measurement of the sideband rejection indicates that the sideband rejection better than 10 dB over 90% of the observational band.
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| 8. |
- Desmaris, Vincent, 1977, et al.
(författare)
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All-metal micromachining for the fabrication of sub-millimetre and THz waveguide components and circuits
- 2008
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Ingår i: Journal of Micromechanics and Microengineering. ; 18, s. 095004-
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Tidskriftsartikel (refereegranskat)abstract
- A novel technology for the manufacturing of micromachined all-metal waveguide circuits and structures for frequency bands ranging from 200 up to 7000 GHz (sub-millimetre and THz) is presented. The waveguide circuits are formed by using metal electroplating with preceding sputtering of a thin metal film seed layer over a photo-lithographically patterned thick SU-8 photoresist. The process provides the possibility of making three-dimensional structures via facilitating multi-level (layered) designs. The surface roughness of the THz waveguide structure was demonstrated to be as low as 30 nm. This technology was used to build astate-of-the-art waveguide balanced 1.3 THz hot electron bolometer mixer and other applications for radio astronomy instrumentation.
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| 9. |
- Desmaris, Vincent, 1977, et al.
(författare)
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Characterization of GaN-based Low Noise Amplifiers at Cryogenic Temperatures
- 2019
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Ingår i: ISSTT 2019 - 30th International Symposium on Space Terahertz Technology, Proceedings Book. ; , s. 67-68
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present the first characterization of GaN-based Low-Noise Amplifiers (LNAs) at cryogenic temperatures for prospective use in radio-astronomy receivers. Both commercial and prototype LNAs fabricated in-house demonstrate a nine-fold improvement of their room-temperature noise performance when cooled to about 10 K. Very promising noise temperatures of about 8 K were measured without any specific optimization of the LNA design for cryogenic operation.
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| 10. |
- Desmaris, Vincent, 1977, et al.
(författare)
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Microfabrication Technology for All-Metal Sub-mm and THz Waveguide Receiver Components
- 2008
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Ingår i: In Proceedings of The 19th International Symposium on Space Terahertz Technology, Groningen, 28-30 April, 2008, ed. W. Wild, Space Research Organization of the Netherlands (SRON). ; part I, s. 342-345
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Konferensbidrag (refereegranskat)abstract
- A novel technology for manufacturing of micromachined all-metal waveguide circuits and structures for the frequency band from 200 up to 7000 GHz (Sub-Millimeter and THz) is presented. The waveguide circuits are formed using metal electroplating with preceding sputtering of a thin metal film seed layer over a photo-lithographically patterned thick SU-8 photo-resist. The process provides possibility of making 3-dimensional structures via facilitating of multi-level (layered) designs. Surface roughness of the THz waveguide structure was demonstrated to be below 0.1 µm. This technology was used to build a state-of-the art waveguide balanced 1.3 THz Hot Electron Bolometer mixer and other application for radio astronomy instrumentation.
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