| 1. |
- Belitsky, Victor, 1955, et al.
(författare)
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Facility Heterodyne Receiver for the Atacama Pathfinder Experiment Telescope
- 2007
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Ingår i: Proceedings of Joint 32nd International Conference on Infrared Millimeter Waves and 15th International conference on Terahertz Electronics, Sept 3-7, 2007, City Hall, Cardiff, Wales, UK. ; , s. 326-328
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Konferensbidrag (refereegranskat)
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| 2. |
- 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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| 3. |
- 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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| 4. |
- Lapkin, Igor, 1963, et al.
(författare)
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Optics Design and Verification for the APEX Swedish Heterodyne Facility Instrument (SHeFI)
- 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. 351-357
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Konferensbidrag (refereegranskat)abstract
- We present the design and verification of the receiver optics for the Single-Pixel HeterodyneFacility Instrument (SHFI) of the APEX telescope [1]. The SHFI is designed to cover thefrequency band 211 – 1390 GHz in 6 receiver channels. Four of the receiver channels have beendesigned, installed and characterized: 211-275 GHz (Band 1); 275-370 GHz (Band 2); 385-500 GHz (Band 3); 1250-1390 GHz (Band T2). The first three bands employ 2SB SIS mixertechnology and Band T2 employs HEB mixers in a waveguide balanced mixer configuration.The entire optics design was driven by the receiver position in the telescope Nasmyth cabin“A” (Fig.1) and the aperture limit of Ø150 mm, introduced by the elevation encoder inside theNasmyth tube A. This layout and the telescope geometry (~ 6 m distance from the focal plane tothe Cabin A) lead us to choose a single-pixel configuration and required using intermediateoptics with long focal distances. The common optics path, coupling the receivers to theCassegrain sub-reflector, consists of the three offset ellipsoidal mirrors, M3, M6, M8s, and threeflat mirrors, F4, F5, and F7s. The combination M3 and M6 via flat F4, F5, creates a Gaussiantelescope, providing frequency-independent re-imaging of the antenna focal plane from theCassegrain cabin into the Nasmyth cabin A. Switching between channels is achieved by theprecision rotating of the active mirror M8s. The mirror M8s in combination with each channelactive mirror M10 provides re-imaging of the secondary onto the feed horn aperture of theselected channel. Such a configuration provides frequency independent illumination of thesecondary with the edge taper -12dB. The angular position of the flat mirrors F9 is adjustable andgives additional possibility of fine-tuning of the beam alignment from the common optics toevery receiver channels.Verification of the optical designthrough measurements is essential inorder to align the beams from thecryostat windows to the commonoptics to minimize loss in thequasioptical guiding system. In orderto verify the design of the cold optics(corrugated horn + M10) in terms ofGaussian beam parameters, a newwideband vector field measurementsystem was developed [2]. Vectorfield measurements were performedfor band 1, 2, and 3, and scalarmeasurements were employed for theTHz band.
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| 5. |
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| 6. |
- Meledin, Denis, 1974, et al.
(författare)
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APEX Band T2: A 1.25 – 1.39 THz Waveguide Balanced HEB Receiver
- 2008
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Ingår i: 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. 162-166
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Konferensbidrag (refereegranskat)abstract
- A waveguide 1.25 - 1.39 THz Hot Electron Bolometer (HEB) balanced receiver was successfully developed, characterized and installed at the Atacama Pathfinder EXperiment (APEX) telescope. The receiver employs a quadrature balanced scheme using a waveguide 90-degree 3 dB RF hybrid, HEB mixers and a 180-degree IF hybrid. The HEB mixers are based on ultrathin NbN film deposited on crystalline quartz with a MgO buffer layer. Integrated into the multi-channel APEX facility receiver (SHeFI), the results presented here demonstrate exceptional performance; a receiver noise temperature of 1000 K measured at the telescope at the center of the receiver IF band 2-4 GHz, and at an LO frequency of 1294 GHz. Stability of the receiver is in line with the SIS mixer bands of the SHeFI, and gives a spectroscopic Allan time of more than 200 s at 1382 GHz with a noise bandwidth of 1 MHz.
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| 7. |
- Monje, Raquel, 1979, et al.
(författare)
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A 0.5 THz Sideband Separation SIS Mixer for APEX Telescope
- 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 II, s. 439-443
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Konferensbidrag (refereegranskat)abstract
- We present the design and the experimental results of a fixed-tuned sideband-separating superconductor-insulator-superconductor (SIS) mixer for 385 - 500 GHz. The sideband separation is achieved using a quadrature scheme, where two separate DSB mixer blocks are combined with an intermediate waveguide component containing the LO waveguide distribution circuitry and RF waveguide hybrid. The intermediate waveguide piece is fabricated by using copper micromachining, which gives dimensions’ accuracy better than 1 μm. The RF signal coming from the waveguide hybrid is coupled to the SIS junctions through an E-probe with integrated bias-T. We implemented an on-chip LO injection solution, where the LO coupler is integrated onto the mixer chip and fabricated together with the SIS junction and the tuning circuitry. The on-chip LO coupler is made as a combination of superconducting microstrip lines and slot-lines (branches), which gives almost a lossless solution. With the fabrication accuracy better than 0.5 μm by using optical lithography, the circuitry is proven to give a good performance following the simulations expectations.
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| 8. |
- Nyström, Olle, 1979, et al.
(författare)
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Optics Design and Verificatgion for the APEX Swedish Heterodyne Facility Instrument (SHeFI)
- 2009
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Ingår i: Journal of Infrared, Millimeter, and Terahertz Waves. - : Springer Science and Business Media LLC. - 1866-6892 .- 1866-6906. ; 30:7, s. 746-761
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present the design and verification of the optics of the Swedish Heterodyne Facility Instrument (SHeFI) receiver installed in the Atacama Pathfinder EXperiment (APEX) telescope during spring 2008. SHeFI is located in the Nasmyth instrumentation Cabin A (NCA). The receiver has been designed to have 6 frequency channels, of which four receiver channels have been built, and characterized: 211-275 GHz(Band 1), 275-370 GHz (Band 2), 385-500 GHz (Band 3), and 1250-1390 GHz (Band T2). Bands 1, 2, and T2 are installed at the telescope and are currently in operation. The optical design is driven by the requirement of frequency independent illumination of the secondary with -12 dB edge taper for each frequency channel and the limitation (beam clearance through the Nasmyth tube and the elevation encoder) imposed by the receiver position in the NCA. This paper describes the design approach, optimization, and verification of the optical system, coupling each individual receiving beam to the common optics of the telescope.
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| 9. |
- Vassilev, Vessen, 1969, et al.
(författare)
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A Swedish heterodyne facility instrument for the APEX telescope
- 2008
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 490:3, s. 1157-1163
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Tidskriftsartikel (refereegranskat)abstract
- In March 2008, the APEX facility instrument was installed on the telescope at the site of Lliano Chajnantor in northern Chile. The main objective of the paper is to introduce the new instrument to the radio astronomical community. It describes the hardware configuration and presents some initial results from the on-sky commissioning.The heterodyne instrument covers frequencies between 211 GHz and 1390 GHz divided into four bands. The first threebands are sideband-separating mixers operating in a single sideband mode and based on superconductor-insulator-superconductor (SIS) tunnel junctions. The fourth band is a hot-electron bolometer, waveguide balanced mixer. All bands are integrated in a closedcycle temperature-stabilized cryostat and are cooled to 4 K.We present results from noise temperature, sideband separation ratios, beam, and stability measurements performed on the telescope as a part of the receiver technical commissioning. Examples of broad extragalactic lines are also included.
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| 10. |
- Amils, R. I., et al.
(författare)
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Compact cryogenic wide-band balanced amplifiers with superconducting 90° hybrids for the IF of submillimeter-wave SIS mixers
- 2019
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Ingår i: ISSTT 2019 - 30th International Symposium on Space Terahertz Technology, Proceedings Book. ; , s. 57-62
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Konferensbidrag (refereegranskat)abstract
- The pressing demand for mm-wave cryogenic radio astronomy receivers with increasing instantaneous bandwidth has spurred interest in more complex intermediate frequency amplifier configurations, like the balanced amplifier, as the traditional options have increasing difficulties to comply either with the noise or the input matching specifications. This solution is typically penalized by the slight increment in noise produced by the quadrature hybrid losses. We propose a balanced amplifier using a novel 3 dB quadrature hybrid coupler design with superconducting lines. The prototype unit built for the 4-12 GHz band integrates in the same module the hybrid coupler chips, the low noise amplifiers and the bias circuitry. The mechanical design allows for an independent testing of the individual amplifiers. The average noise temperature is 4.4 K, only 0.3 K more than the average of its amplifiers. The input reflection improves more than 10 dB. This compact balanced amplifier is also compared with a non-integrated version, showing an improvement in noise and reflection. It has been tested in a complete mm-wave receiver, with advantage over other IF schemes.
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