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Author Semenov, A.; Richter, H.; Hübers, H.-W.; Petrenko, D.; Tretyakov, I.; Ryabchun, S.; Finkel, M.; Kaurova, N.; Gol’tsman, G.; Risacher, C.; Ricken, O.; Güsten, R.
Title Optimization of the intermediate frequency bandwidth in the THz HEB mixers Type Abstract
Year 2014 Publication Proc. 25th Int. Symp. Space Terahertz Technol. Abbreviated Journal (down) Proc. 25th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 54
Keywords NbN HEB mixer
Abstract We report on the studies of the intermediate frequency (IF) bandwidth of quasi-optically coupled NbN hot-electron bolometer (HEB) mixers which are aimed at the optimization of the mixer performance at terahertz frequencies. Extension of the IF bandwidth due to the contribution of electron diffusion to the heat removal from NbN microbolometers has been already demonstrated for NbN HEBs at subterahertz frequencies. However, reducing the size of the microbolometer causes degradation of the noise temperature. Using in-situ multilayer manufacturing process we succeeded to improve the transparency of the contacts for electrons which go away from microbolometer to the metallic antenna. The improved transparency and hence coupling efficiency counterbalances the noise temperature degradation. HEB mixers were tested in a laboratory heterodyne receiver with a narrow-band cold filter which allowed us to eliminate direct detection. We used a local oscillator with a quantum cascade laser (QCL) at a frequency of 4.745 THz [1] which was developed for the H-Channel of the German Receiver for Astronomy at Terahertz frequencies (GREAT). Both the noise and gain bandwidth were measured in the IF range from 0.5 to 8 GHz using the hot-cold technique and preliminary calibrated IF analyzer with a tunable microwave filter. For optimized HEB geometry we found the noise bandwidth as large as 7 GHz. We compare our results with the conventional and the hot-spot mixer models and show that further extension of the IF bandwidth should be possible via improving the sharpness of the superconducting transition. The cross characterization of the HEB mixer was performed in the test bed of GREAT at the Max-Planck-Institut für Radioastronomie with the same QCL LO and delivered results which were consistent with the laboratory studies.
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Notes Approved no
Call Number Serial 1359
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Author Semenov, A. D.; Sergeev, A. V.; Kouminov, P.; Goghidze, I. G.; Heusinger, M. A.; Nebosis, R. S.; Gol'tsman, G. N.; Gershenzon, E. M.; Renk, K. F.
Title Transparency of YBCO film/substrate interfaces for thermal phonons determined by photoresponse measurements Type Conference Article
Year 1993 Publication Proc. 1st European Conf. on Appl. Supercond. Abbreviated Journal (down) Proc. 1st European Conf. on Appl. Supercond.
Volume 2 Issue Pages 1443-1446
Keywords YBCO HTS detectors
Abstract Direct measurements of the thermal boundary resistance were performed by means of the stationary method. In this approach the temperature of an electrically heated film is controlled by its dc resistance while an additional film on the same substrate is used as a thermometer monitoring substrate temperature. The temperature field in the substrate is then calculated to deduce the Kapitza temperature step at the interface between the heated strip and the substrate. The main statement of all afore-said papers is that experimental values of the thermal boundary resistance are too large to be explained by the acoustic mismatch model. In this paper we investigate transparency of YBaCuO film/substrate interfaces for thermal phonons by means of photoresponse measurements. We show that our data are in reasonable agreement with the acoustic mismatch theory.
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Corporate Author Thesis
Publisher Place of Publication Editor Freyhardt, H. C.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN 3-88355-197-X Medium
Area Expedition Conference 1st European conference on applied superconductivity
Notes Approved no
Call Number Serial 1661
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Author Cherednichenko, S.; Drakinskiy, V.; Baubert, J.; Lecomte, B.; Dauplay, F.; Krieg, J.-M.; Delorme, Y.; Feret, A.; Hübers, H.-W.; Semenov, A. D.; Gol’tsman, G. N.
Title 2.5 THz multipixel heterodyne receiver based on NbN HEB mixers Type Abstract
Year 2007 Publication Proc. 18th Int. Symp. Space Terahertz Technol. Abbreviated Journal (down) Proc. 18th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 112
Keywords NbN HEB mixers
Abstract A 16 pixel heterodyne receiver for 2.5 THz has been developed based on NbN superconducting hot-electron bolometer (HEB) mixers. The receiver uses a quasioptical RF coupling approach where HEB mixers are integrated into double dipole antennas on 1.5μm thick Si3N4 / SiO2 membranes. Spherical mirrors (one per pixel) and backshort distance from the antenna have been used to design the output mixer beam profile. The camera design allows all 16 pixel IF readout in parallel. Measurements of the mixers sensitivity and the input RF band are presented, and compared against calculations.
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Notes Approved no
Call Number Serial 1419
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Author Semenov, A.; Richter, H.; Smirnov, A.; Günther, B.; Hübers, H.-W.; Il’in, K.; Siegel, M.; Gol’tsman, G.; Drakinskiy, V.; Merkel, H.; Karamarkovic, J.
Title Development of HEB mixers for GREAT and for security screening Type Abstract
Year 2007 Publication Proc. 18th Int. Symp. Space Terahertz Technol. Abbreviated Journal (down) Proc. 18th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 184
Keywords NbN HEB mixers, GREAT
Abstract We report the study on the quasioptical coupling efficiency and the gain bandwidth of NbN hot-electron bolometer mixers developed for the 4.7 THz channel of the German receiver for Astronomy at THz-frequencies (GREAT) and for security screening at subterahertz frequencies. Radiation coupling efficiency and directive properties of integrated lens antennas with log-spiral, log-periodic and double-slot planar feeds coupled to a hot-electron bolometer were experimentally studied at frequencies from 1 THz to 6 THz and compared with simulations based on the method of moments and the physical-optics ray tracing. For all studied antennas the modeled spectral dependence of the coupling efficiency fits to the experimental data obtained with both Fourier transform spectroscopy and noise temperature measurements only if the complex impedance of the bolometer is explicitly taken into account. Our experimental data did not indicate any noticeable contribution of the quantum noise to the system noise temperature. The experimentally observed deviation of the beam pattern from the model prediction increases with frequency and is most likely due to a non- ideality of the presently used lenses. Study of the intermediate frequency mixer gain at local oscillator (LO) frequencies between 2.5 THz and 0.3 THz showed an increase of the gain bandwidth at low LO frequencies that was understood as the contribution of the direct interaction of magnetic vortices with the radiation field. We have found that the non- homogeneous hot-spot model more adequately describes variation of the intermediate frequency bandwidth with the applied local oscillator power than any of uniform mixer models. The state-of-the-day performance of the GREAT 4.7-THz channel and the 0.8-THz security scanner will be presented.
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Publisher Place of Publication Editor
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Notes Approved no
Call Number Serial 1420
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Author Yagoubov, P. L.; Hoogeveen, R. W. M.; Maurellis, A. M.; Mair, U.; Krocka, M.; Wagner, G.; Birk, M.; Hiibers, H.-W.; Richter, H.; Semenov, A.; Gol'tsman, G.; Voronov, B.; Koshelets, V.; Shitov, S.; Ellison, B.; Kerridge, B.; Matheson, D.; Alderman, B.; Harman, M.; Siddans, R.; Reburn, J.
Title TELIS — development of a new balloon borne THz/submm heterodyne limb sounder Type Conference Article
Year 2003 Publication Proc. 14th Int. Symp. Space Terahertz Technol. Abbreviated Journal (down) Proc. 14th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 204-214
Keywords limb-sounder, TELIS
Abstract We present a design concept for a new state-of-the-art balloon borne atmospheric monitor that will allow enhanced limb sounding of the Earth's atmosphere within the submillimeter and far-infrared wavelength spectral range: TELIS, TErahertz and submm LImb Sounder. The instrument is being developed by a consortium of major European institutes that includes the Space Research Organisation of the Netherlands (SRON), the Rutherford Appleton Laboratory (RAL) in the United Kingdom and the Deutschen Zentrum far Luft- und Raumfahrt (DLR) in Germany (lead institute). TELIS will utilise state-of-the-art superconducting heterodyne technology and is designed to be a compact, lightweight instrument capable of providing broad spectral coverage, high spectral resolution and long flight duration (-24 hours duration during a single flight campaign). The combination of high sensitivity and extensive flight duration will allow evaluation of the diurnal variation of key atmospheric constituents such as OH, HO,, C10, BrO together will longer lived constituents such as 0 3 , HCL and N 2 0. Furthermore, TELIS will share a common balloon platform to that of the MIPAS-B Fourier Transform Spectrometer, developed by the Institute of Meteorology and Climate research of the University of Karlsruhe, Germany. MIPAS-B will provide simultaneous and complementary spectral measurements over an extended spectral range. The combination of the TELIS and MIPAS instruments will provide atmospheric scientists with a very powerful observational tool. TELIS will serve as a testbed for new cryogenic heterodyne detection techniques, and as such it will act as a prelude to future spacebome instruments planned by the European Space Agency (ESA).
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Notes Approved no
Call Number Serial 1499
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