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Author Hübers, H.-W.; Semenov, A.; Richter, H.; Birk, M.; Krocka, M.; Mair, U.; Smirnov, K.; Gol’tsman, G.; Voronov, B.
Title Terahertz Heterodyn Receiver with a hot-electron bolometer mixer Type Conference Article
Year 2002 Publication Far-IR, Sub-mm & MM Detector Technology Workshop Abbreviated Journal Far-IR, Sub-mm & MM Detector Technology Workshop
Volume (up) Issue Pages 3-24
Keywords NbN HEB mixers
Abstract During the past decade major advances have been made regarding low noise mixers for terahertz (THz) heterodyne receivers. State of the art hot-electron-bolometer (HEB) mixers have noise temperatures close to the quantum limit and require less than a µW power from the local oscillator (LO). The technology is now at a point where the performance of a practical receiver employing such mixer, rather than the figures of merit of the mixer itself, are of major concern. We have incorporated a phonon-cooled NbN HEB mixer in a 2.5 THz heterodyne receiver and investigated the performance of the receiver. This yields important information for the development of heterodyne receivers such as GREAT (German receiver for astronomy at THz frequencies aboard SOFIA) [1] and TELIS (Terahertz limb sounder), a balloon borne heterodyne receiver for atmospheric research [2]. Both are currently under development at DLR.
Address
Corporate Author Thesis
Publisher NASA Place of Publication Editor Wolf, U.; Farhoomand, J.; McCreight, C.R.
Language Summary Language Original Title
Series Editor Series Title NASA CP Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Volume: 211408 Approved no
Call Number Serial 1537
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Author Semenov, A.; Hübers, H.-W.; Engel, A.; Gol’tsman, G.
Title Superconducting quantum detector for far infrared astronomy Type Conference Article
Year 2002 Publication Far-IR, Sub-mm & MM Detector Technology Workshop Abbreviated Journal Far-IR, Sub-mm & MM Detector Technology Workshop
Volume (up) Issue Pages 3-49
Keywords SQD
Abstract We present the concept of the superconducting quantum detector for astronomy. Response to a single absorbed photon appears due to successive formation of a normal spot and phase-slip-centres in a narrow strip carrying sub-critical supercurrent. The detector simultaneously has a moderate energy resolution and a variable cut-off wavelength depending on both the material used and operation conditions. We simulated performance of the background-limited direct detector having the 100-micrometer cut-off wavelength. Low dark count rate will allow to realise 10-21 W Hz-1/2 noise equivalent power at 4 K background radiation. The detection mechanism provides a moderate 1/20 energy resolution at 50-micrometer wavelength.
Address
Corporate Author Thesis
Publisher NASA Place of Publication Editor Wolf, J.; Farhoomand, J.; McCreight, C.R.
Language Summary Language Original Title
Series Editor Series Title NASA CP Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Volume: 211408 Approved no
Call Number Serial 1538
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Author Yagoubov, P.; Hübers, H.-W.; Gol’tsman, G.; Semenov, A.; Gao, J.; Hoogeveen, R.; de Graauw, T.; Birk, M.; Selig, A.; de Korte, P.
Title Hot-electron bolometer mixers – technology for far-infrared heterodyne instruments in future atmospheric chemistry missions Type Conference Article
Year 2001 Publication Proc. 3rd Int. Symp. Submillimeter Wave Earth Observation From Space Abbreviated Journal Proc. 3rd Int. Symp. Submillimeter Wave Earth Observation From Space
Volume (up) Issue Pages 57-69
Keywords HEB mixers
Abstract
Address Delmenhorst
Corporate Author Thesis
Publisher Logos-Verlag Place of Publication Editor Buehler, S.; Berlin
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 3-89722-700-2 Medium
Area Expedition Conference International Symposium on Submillimeter Wave Earth Observation from Space, ISSMWEOS01
Notes Approved no
Call Number Serial 1549
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Author Hübers, Heinz-Wilhelm; Semenov, Alexei; Schubert, Josef; Gol'tsman, Gregory; Voronov, Boris; Gershenzon, Evgeni
Title Performance of the phonon-cooled hot-electron bolometric mixer between 0.7 THz and 5.2 THz Type Conference Article
Year 2000 Publication Proc. 8-th Int. Conf. on Terahertz Electronics Abbreviated Journal Proc. 8-th Int. Conf. on Terahertz Electronics
Volume (up) Issue Pages 117-119
Keywords NbN HEB mixers
Abstract We report on the phonon cooled NbN hot electron bolometer as mixer in the terahertz frequency range. Its hybrid antenna consists of a hyperhemispheric silicon lens and a logarithmic-spiral feed antenna. Noise temperatures have been measured between 0.7 THz and 5.2 THz. A quarter wavelength layer of Parylene works as antireflection coating for the silicon lens and reduces the noise temperature by about 30. It was found that the antenna pattern at 2.5 THz is determined by the feed antenna and not by the diameter of the lens.
Address Darmstadt, Germany
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference International Conference on Terahertz Electronics [8th], Held inDarmstadt, Germany on 28-29 September 2000
Notes Approved no
Call Number Serial 1553
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Author Darula, Marian; Semenov, Alex D.; Hübers, Heinz-Wilhelm; Schubert, Josef
Title Quasioptical high-Tc superconductor Josephson mixer at terahertz frequencies Type Abstract
Year 2000 Publication Proc. 11th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 11th Int. Symp. Space Terahertz Technol.
Volume (up) Issue Pages 515
Keywords HTS Josephson mixers
Abstract Mixers based on Josephson junctions from conventional superconductor materials have demonstrated excellent performance at subgap frequencies. The advantages of Josephson mixers are low optimal power of the local oscillator and large intermediate frequency bandwidth but their noise temperature increases dramatically at frequencies corresponding to the energy gap of the superconductor, which is typically below 1 THz for widely used materials. The large energy gap of oxide superconductors makes them promising candidates for development of terahertz Josephson mixers. Here we report on experimental study of the quasioptical mixer utilizing bicrystal Josephson junction from high-transition-temperature YBa 2 Cu 3 O 7-δ film. Junctions with a width of 2 µm were fabricated from 100 nm thick laser ablated films on bicrystal MgO substrates and had the and the J C R n product of about 2 mV at 4.2 K. The planar complementary logarithmic spiral antenna incorporated into co-planar waveguide was patterned from 200 nm thick gold film thermally evaporated in situ on top of the YBa 2 Cu 3 O 7-δ film. The mixer chip was clamped to the extended hemispherical silicon lens. Performance of the mixer was investigated at 4.5 K bath temperature. We used FIR laser as a local oscillator at frequencies 0.698 and 2.52 THz. System noise temperature (DSB) was determined from Y-factor measured with 300 K and 77 K loads. At 0.698 THz the lowest noise temperature 1750 K was observed when the mixer was biased with the fixed current to the region in the vicinity of either the first Shapiro step or the critical current. Between these two bias points the noise temperature increased to ≈ 20000 K. As function of the local oscillator power the noise temperature reached the minimum when the critical current was suppressed to the half of its equilibrium value. Power of the local oscillator absorbed by the mixer at optimal operation was of the order 100 nW. The present design of our antenna limits the upper operation frequency to the value of 1.8 THz. Nevertheless, we clearly observed Shapiro steps at the frequency 2.52 THz. Bearing in mind an improved design of the antenna, we estimate the 3000 K DSB noise temperature at this frequency.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1555
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