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Author Semenov, Alexei; Richter, Heiko; Smirnov, Konstantin; Voronov, Boris; Gol'tsman, Gregory; Hübers, Heinz-Wilhelm
Title The development of terahertz superconducting hot-electron bolometric mixers Type Journal Article
Year 2004 Publication Supercond. Sci. Technol. Abbreviated Journal Supercond. Sci. Technol.
Volume 17 Issue 5 Pages 436-439
Keywords NbN HEB mixers
Abstract We present recent advances in the development of NbN hot-electron bolometric (HEB) mixers for flying terahertz heterodyne receivers. Three important issues have been addressed: the quality of the source NbN films, the effect of the bolometer size on the spectral properties of different planar feed antennas, and the local oscillator (LO) power required for optimal operation of the mixer. Studies of the NbN films with an atomic force microscope indicated a surface structure that may affect the performance of the smallest mixers. Measured spectral gain and noise temperature suggest that at frequencies above 2.5 THz the spiral feed provides better overall performance than the double-slot feed. Direct measurements of the optimal LO power support earlier estimates made in the framework of the uniform mixer model.
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Notes Approved no
Call Number (up) Serial 357
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Author Yagoubov, Pavel; Kroug, Matthias; Merkel, Harald; Kollberg, Erik; Schubert, Josef; Hübers, Heinz-Wilhelm
Title NbN hot electron bolometric mixers at frequencies between 0.7 and 3.1 THz Type Journal Article
Year 1999 Publication Supercond. Sci. Technol. Abbreviated Journal Supercond. Sci. Technol.
Volume 12 Issue 11 Pages 989-991
Keywords NbN HEB mixers
Abstract The performance of NbN-based phonon-cooled hot electron bolometric (HEB) quasioptical mixers is investigated in the 0.7-3.1 THz frequency range. The devices are made from a 3.5-4 nm thick NbN film on high resistivity Si and integrated with a planar spiral antenna on the same substrate. The length of the bolometer microbridge is 0.1-0.2 µm; the width is 1-2 µm. The best results of the DSB receiver noise temperature measured at 1.5 GHz intermediate frequency are: 800 K at 0.7 THz, 1100 K at 1.6 THz, 2000 K at 2.5 THz and 4200 K at 3.1 THz. The measurements were performed with a far infrared laser as the local oscillator (LO) source. The estimated LO power requirement is less than 500 nW at the receiver input. First results on spiral antenna polarization measurements are reported.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (up) Serial 295
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Author Semenov, A. D.; Hübers, Heinz-Wilhelm; Richter, H.; Birk, M.; Krocka, M.; Mair, U.; Vachtomin, Yu. B.; Finkel, M. I.; Antipov, S. V.; Voronov, B. M.; Smirnov, K. V.; Kaurova, N. S.; Drakinski, V. N.; Gol'tsman, G. N.
Title Superconducting hot-electron bolometer mixer for terahertz heterodyne receivers Type Journal Article
Year 2003 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal
Volume 13 Issue 2 Pages 168-171
Keywords NbN HEB mixers
Abstract We present recent results showing the development of superconducting NbN hot-electron bolometer mixer for German receiver for astronomy at terahertz frequencies and terahertz limb sounder. The mixer is incorporated into a planar feed antenna, which has either logarithmic spiral or double-slot configuration, and backed on a silicon lens. The hybrid antenna had almost frequency independent and symmetric radiation pattern slightly broader than expected for a diffraction limited antenna. At 2.5 THz the best 2200 K double side-band receiver noise temperature was achieved across a 1 GHz intermediate frequency bandwidth centred at 1.5 GHz. For this operation regime, a receiver conversion efficiency of -17 dB was directly measured and the loss budget was evaluated. The mixer response was linear at load temperatures smaller than 400 K. Implementation of the MgO buffer layer on Si resulted in an increased 5.2 GHz gain bandwidth. The receiver was tested in the laboratory environment by measuring a methanol emission line at 2.5 THz.
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Notes Approved no
Call Number (up) Serial 343
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Author Semenov, Alexei; Il'yin, Konstantin; Siegel, Michael; Smirnov, Andrey; Pavlov, Sergey; Richter, Heiko; Hübers, Heinz-Wilhelm
Title Intermediate frequency bandwidth of a hot-electron mixer: Comparision with bolometric models Type Conference Article
Year 2006 Publication Proc. 17th Int. Symp. Space Terahertz Technol. Abbreviated Journal
Volume Issue Pages 73-76
Keywords HEB
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Paris, France 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 (up) Serial 537
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Author Semenov, Alexei D.; Hübers, Heinz-Wilhelm; Richter, Heiko; Smirnov, Konstantin; Gol'tsman, Gregory N.; Voronov, Boris M.
Title Superconducting hot-electron bolometer mixer for terahertz heterodyne receivers Type Abstract
Year 2004 Publication Proc. 15th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 15th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 164
Keywords NbN HEB mixers
Abstract A number of on-going astronomical and atmospheric research programs are aimed to the Terahertz (THz) spectral region. At frequencies above about 1.4 THz heterodyne receivers planned for these missions will use superconducting hot-electron bolometers as a mixers. We present current results on the development of superconducting NbN hot- electron bolometer mixer and quasioptical radiation coupling scheme for GREAT (German Receiver for Astronomy at Terahertz Frequencies, to be used aboard of SOFIA) and TELIS (Terahertz Limb Sounder). The mixer is incorporated into hybrid antenna consisting of a planar feed antenna, which has either logarithmic spiral or double-slot configuration, and hyperhemispherical silicon lens. For the log-spiral feed antenna, the double side-band receiver noise temperature of 5500 K was achieved at 4.3 THz. The noise temperature shows less than 3 dB increase in the intermediate frequency band from 4 GHz to 7 GHz. The hybrid antenna had almost frequency independent and symmetric radiation pattern with the beam-width slightly broader than expected for a diffraction limited pattern. Results of FTS measurements in the direct detection regime agreed with the spectral dependence of the noise temperature for spiral antennas with different spacing of inner terminals.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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Area Expedition Conference
Notes Approved no
Call Number (up) Serial 1492
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