RpLab Home

Bibliography database of Radiophysics Laboratory (RpLab)

Home |  Show All |  Simple Search |  Advanced Search
Quick Search:
71-80 of 891 records found matching your query:
toggle visibility Search & Display Options
Select All    Deselect All << 1 2 3 4 5 6 7 8 9 10 >> [11–20]
List View
 | 
Citations
 | 
Details
   print
  Records Links (down)
Author Hajenius, M.; Baselmans, J. J. A.; Gao, J. R.; Klapwijk, T. M.; de Korte 2, P. A. J.; Voronov, B.; Gol’tsman, G. url  openurl
  Title Increased bandwidth of NbN phonon cooled hot electron bolometer mixers Type Conference Article
  Year 2004 Publication Proc. 15th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 15th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 381-386  
  Keywords NbN HEB mixers, IF bandwidth  
  Abstract We study experimentally the IF gain bandwidth of NbN phonon-cooled hot-electron-bolometer (HEB) mixers for a set of devices with different contact structures but an identical NbN film. We observe that the IF bandwidth depends strongly on the exact contact structure and find an IF gain bandwidth of 6 GHz for a device with an additional superconducting layer (NbTiN) in between the active NbN film and the gold contact to the antenna. These results contradict the common opinion that the IF bandwidth is determined by the phonon-escape time between the NbN film and the substrate. Hence we calculate the IF gain bandwidth of a superconducting film using a two-temperature model. We find that the bandwidth increases strongly with operating temperature and is not limited by the phonon escape time. This is because of strong temperature dependence of the phonon specific heat in the NbN film.  
  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 1494  
Permanent link to this record
 
 
Author Hajenius, M.; Baselmans, J. J. A.; Gao, J. R.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol’tsman, G. url  openurl
  Title Improved NbN phonon cooled hot electron bolometer mixers Type Conference Article
  Year 2003 Publication Proc. 14th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 14th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 413-423  
  Keywords NbN HEB mixers  
  Abstract NbN phonon-cooled hot electron bolometer mixers (HEBs) have been realized with negligible contact resistance to Au pads. By adding either a 5 nm Nb or a 10 nm NbTiN layer between the Au and NbN, to preserve superconductivity in the NbN under the Au contact pad, superior noise temperatures have been obtained. Using DC I,V curves and resistive transitions in combination with process parameters we analyze the nature of these improved devices and determine interface transparencies.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Tucson, USA 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 337  
Permanent link to this record
 
 
Author Finkel, Matvey; Vachtomin, Yuriy; Antipov, Sereey; Drakinski, Vladimir; Kaurova, Natalia; Voronov, Boris; Goltsman, Greeory url  openurl
  Title Gain bandwidth and noise temperature of NbTiN HEB mixer Type Conference Article
  Year 2003 Publication Proc. 14th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 14th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 276-285  
  Keywords NbTiN HEB mixer  
  Abstract We have determined that the gain bandwidth of phonon-cooled HEB mixer employing NbTiN films deposited on MgO layer over Si substrate is limited b y the escape of phonons to the substrate. The cut-off frequencies of 1 um long devices operating at T 71, based on 3.5 nm. 4 nm and 10 nm thick films amount to 400 Mk. 300 MHz, and 100 MHz, respectivel y . The gain bandwidth of 0.13 . um long devices fabricated from 3.5 nm thick film is larger and amounts to 0.8 GIL; at the optimal operating point and to 1.5 GIL: at larger bias. The increase of the gain bandwidth from 400 MHz up to 1.5 GH: with the change of bridge length is attributed to diffusion cooling. A double sideband noise temperature of 4000 K was obtained for heterodyne receiver utilizing pilot NbTiN HEB mixer (not optimized for normal state resistance) operating at the local oscillator frequency of 2.5 THz.  
  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 1500  
Permanent link to this record
 
 
Author Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol'tsman, G. url  openurl
  Title Noise performance of NbN hot electron bolometer mixers at 2.5 THz and its dependence on the contact resistance Type Conference Article
  Year 2003 Publication Proc. 14th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 14th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 11-19  
  Keywords NbN HEB mixers  
  Abstract NbN hot electron bolometer mixers (HEBM) are at this moment the best heterodyne receivers for frequencies above 1 Thz. However, the fabrication procedure of these devices is such that the quality of the interface between the NbN superconducting film and the contact structure is not under good control. The result is a low transparency interface between the bolometer itself and the contact/antenna structure. In this paper we report a detailed experimental study on a novel idea to increase the transparency of this interface. This leads to a record sensitivity and more reproducible performance. We compare identical bolometers, coupled with a spiral antenna, with different NbN bolometer-contact pad interfaces. We find that cleaning the NbN interface alone results in an increase in the noise temperature. However, cleaning the NbN interface and adding a thin additional superconductor prior to the gold contact deposition improves the noise temperature of the HEBm with more than a factor of 2. A device with a contact pad on top of an in-situ cleaned NbN film consisting of 10 nm of NbTiN and 40 nm of gold has a DSB noise temperature of 1050 K at 2.5 THz.  
  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 1497  
Permanent link to this record
 
 
Author Semenov, Alexei D.; Hiibers, Heinz-Wilhelm; Richter, Heiko; Smirnov, Konstantin; Gol'tsman, Gregory N.; Kaurova, Natalia; Voronov, Boris M. url  openurl
  Title Superconducting hot-electron bolometer mixer for terahertz heterodyne receivers Type Conference Article
  Year 2003 Publication Proc. 14th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 14th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 33-40  
  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 recent results of the terahertz antenna development of superconducting NbN hot-electron bolometer mixer 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 hyper hemispherical silicon lens. The hybrid antenna showed almost frequency independent and symmetric radiation pattern with the beam-width slightly broader than expected for diffraction limited antenna. The noise temperature as well as its spectral dependence changes with the bolometer sizes that provides additional tool for mixer optimization. FTS spectra measured in the direct detection regime agreed with the noise temperature spectra.  
  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 1498  
Permanent link to this record
 
 
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. url  openurl
  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 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).  
  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 1499  
Permanent link to this record
 
 
Author Tong, C.-Y. Edward; Meledin, Denis; Blundell, Raymond; Erickson, Neal; Kawamura, Jonathan; Mehdi, Imran; Gol'tsman, Gregory url  openurl
  Title A 1.5 THz hot-electron bolometer mixer operated by a planar diode-based local oscillator Type Abstract
  Year 2003 Publication Proc. 14th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 14th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 286  
  Keywords waveguide NbN HEB mixers  
  Abstract We describe a 1.5 THz heterodyne receiver based on a superconductin g hot-electron bolometer mixer, which is pumped by an all-solid-state local oscillator chain. The bolometer is fabricated from a 3.5 nm-thick niobium nitride film deposited on a quartz substrate with a 200 nm-thick magnesium oxide buffer layer. The bolometer measures 0.15 fun in width and 1.5 1..tm in length. The chip consisting of the bolometer and mixer circuitry is incorporated in a fixed-tuned waveguide mixer block with a corru g ated feed horn. The local oscillator unit comprises of a cascade of four planar doublers followin g a MMIC-based W-band power amplifier. The local oscillator is coupled to the mixer using a Martin-Puplett interferometer. The local oscillator output power needed for optimal receiver performance is approximately 1 to 2 11W, and the chain is able to provide this power at a number of frequency points between 1.45 and 1.56 THz. By terminating the rf input with room temperature and 77 K loads, a Y-factor of 1.11 (DSB) has been measured at a local oscillator frequency of 1.476 THz at 3 GHz intermediate 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 1501  
Permanent link to this record
 
 
Author Smirnov, K. V.; Vachtomin, Yu. B.; Antipov, S. V.; Maslennikov, S. N.; Kaurova, N. S.; Drakinsky, V. N.; Voronov, B. M.; Gol'tsman, G. N.; Semenov, A. D.; Richter, H.; Hubers, H.-W. url  openurl
  Title Noise and gain performance of spiral antenna coupled HEB mixers at 0.7 THz and 2.5 THz Type Conference Article
  Year 2003 Publication Proc. 14th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 14th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 405-412  
  Keywords NbN HEB mixers  
  Abstract Noise and gain performance of hot electron bolometer (HEB) mixers based on ultrathin superconducting NbN films integrated with a spiral antenna was studied. The noise temperature measurements for two samples with different active area of 3 p.m x 0.24 .tni and 1.3 1..tm x 0.12 1.tm were performed at frequencies 0.7 THz and 2.5 THz. The best receiver noise temperatures 370 K and 1600 K, respectively, have been found at these frequencies. The influence of contact resistance between the superconductor and the antenna terminals on the noise temperature of HEB is discussed. The noise and gain bandwidth of 5GHz and 4.2 GHz, respectively, are demonstrated for similar HEB mixer at 0.75 THz.  
  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 1502  
Permanent link to this record
 
 
Author Vahtomin, Yuriy B.; Finkel, Matvey I.; Antipov, Sergey V.; Voronov, Boris M.; Smirnov, Konstantin V.; Kaurova, Natalia S.; Drakinski, Vladimir N.; Gol'tsman, Gregogy N. url  openurl
  Title Gain bandwidth of phonon-cooled HEB mixer made of NbN thin film with MgO buffer layer on Si Type Conference Article
  Year 2002 Publication Proc. 13th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 13th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 259-270  
  Keywords NbN HEB mixers, conversion gain bandwidth  
  Abstract We present recently obtained values for gain bandwidth of NbN HEB mixers for different substrates and film thicknesses and for MgO buffer layer on Si at LO frequency of 0.85-1 THz. The maximal bandwidth, 5.2 GHz, was achieved for the device on MgO buffer layer on Si with a 2 nm thick NbN film. Functional devices based on NbN films of such thickness were fabricated for the first time due to an improvement of superconducting properties of NbN film deposited on MgO buffer layer on Si substrate.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge, MA, USA Editor Harvard university  
  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 325  
Permanent link to this record
 
 
Author Meledin, D.; Tong, C. Y.-E.; Blundell, R.; Kaurova, N.; Smirnov, K.; Voronov, B.; Gol'tsman, G. url  openurl
  Title The sensitivity and IF bandwidth of waveguide NbN hot electron bolometer mixers on MgO buffer layers over crystalline quartz Type Conference Article
  Year 2002 Publication Proc. 13th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 13th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 65-72  
  Keywords waveguide NbN HEB mixers  
  Abstract We have developed and characterized waveguide phonon-cooled NbN Hot Electron Bolometer (FMB) mixers fabricated from a 3-4 nm thick NbN film deposited on a 200nm thick MgO buffer layer over crystalline quartz. Double side band receiver noise temperatures of 900-1050 K at 1.035 THz, and 1300-1400 K at 1.26 THz have been measured at an intermediate frequency of 1.5 GHz. The intermediate frequency bandwidth, measured at 0.8 THz LO frequency, is 3.2 GHz at the optimal bias point for low noise receiver operation.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge, MA, USA Editor Harvard university  
  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 326  
Permanent link to this record
Select All    Deselect All << 1 2 3 4 5 6 7 8 9 10 >> [11–20]
List View
 | 
Citations
 | 
Details
   print
toggle visibility
Save Citations:
Export Records:
Home CQL Search  |  Library Search  |  Show Record  |  Extract Citations Help