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Author Zhang, W.; Li, N.; Jiang, L.; Ren, Y.; Yao, Q.-J.; Lin, Z.-H.; Shi, S.-C.; Voronov, B. M.; Gol’tsman, G. N. url  doi
openurl 
  Title Dependence of noise temperature of quasi-optical superconducting hot-electron bolometer mixers on bath temperature and optical-axis displacement Type (up) Conference Article
  Year 2008 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 6840 Issue Pages 684007 (1 to 8)  
  Keywords NbN HEB mixers, noise temperature, LO power  
  Abstract It is known that the increase of bath temperature results in the decrease of critical current of superconducting hot-electron bolometer (HEB) mixers owing to the depression of superconductivity, thus leading to the degradation of the mixer’s sensitivity. Here we report our study on the effect of bath temperature on the heterodyne mixing performance of quasi-optical superconducting NbN HEB mixers incorporated with a two-arm log-spiral antenna. The correlation between the bath temperature, critical current, LO power requirement and noise temperature is investigated at 0.5 THz. Furthermore, the heterodyne mixing performance of quasi-optical superconducting NbN HEB mixers is examined while there is an optical-axis displacement between the center of the extended hemispherical silicon lens and the superconducting NbN HEB device, which is placed on the back of the lens. Detailed experimental results and analysis are presented.  
  Address  
  Corporate Author Thesis  
  Publisher Spie Place of Publication Editor Zhang, C.; Zhang, X.-C.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference Terahertz Photonics  
  Notes Approved no  
  Call Number Serial 1415  
Permanent link to this record
 
 
Author Ryabchun, Sergey; Tong, Cheuk-yu Edward; Blundell, Raymond; Kimberk, Robert; Gol’tsman, Gregory url  openurl
  Title Stabilisation of a terahertz hot-electron bolometer mixer with microwave feedback control Type (up) Conference Article
  Year 2007 Publication Proc. 18th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 18th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 193-198  
  Keywords waveguide NbN HEB mixers, Allan variance, stability  
  Abstract We report on implementation of microwave feedback control loop to stabilise the performance of an HEB mixer receiver. It is shown that the receiver sensitivity increases by a factor of 4 over a 16-minute scan, and the corresponding Allan time increases up to 10 seconds, as opposed to an open loop value of 1 second. Our experiments also demonstrate that the receiver sensitivity is limited by the intermediate frequency chain.  
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  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 1421  
Permanent link to this record
 
 
Author Jiang, Ling; Miao, Wei; Zhang, Wen; Li, Ning; Lin, Zhen Hui; Yao, Qi Jun; Shi, Sheng-Cai; Svechnikov, Sergey I.; Vakhtomin, Yury B.; Antipov, Sergey V.; Voronov, Boris M.; Kaurova, Natalia S.; Gol'tsman, Gregory N. url  openurl
  Title Characterization of quasi-optical NbN phonon-cooled superconducting HEB mixers Type (up) Conference Article
  Year 2006 Publication Proc. 17th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 17th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 55-58  
  Keywords NbN HEB mixers  
  Abstract In this paper, we thoroughly investigate the performance of quasi-optical NbN phonon-cooled superconducting hot-electron bolometer (HEB) mixers, cryogenically cooled by a close-cycled 4-K refrigerator at 500 GI-1z and 850 GHz. The uncorrected lowest receiver noise Abstract---In temperatures measured are 800 K at 500 CHz without anti-reflection coating, and 1000 K @ 850 GHz with a 50 11M thick Mylar anti-reflection coating. The dependence of receiver noise temperature on the critical current and bath temperature of HEB mixer is also investigated here. Lifetime of quasi-optical superconducting NbN HEB mixers of different volumes, room temperature resistances, and critical temperatures are thoroughly studied. Increased room temperature resistance with time over the initial resistance changes between 1 and 1.2, and the reduced critical current with time over the initial value fluctuates slightly around 0.7 for most HEB mixers even of different volumes, room temperature resistances, and critical temperatures. The critical current degrades sharply vvhile room temperature resistance varies over 1.25.  
  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 1435  
Permanent link to this record
 
 
Author Gao, J.R.; Hiajenius, M.; Yang, Z.Q.; Klapwijk, T.M.; Miao, W.; Shi, S. C.; Voronov, B.; Gortsman, G. url  openurl
  Title Direct comparison of the sensitivity of a spiral and a twin-slot antenna coupled HEB mixer at 1.6 THz Type (up) Conference Article
  Year 2006 Publication Proc. 17th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 17th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 59-62  
  Keywords NbN HEB mixers  
  Abstract To make a direct comparison of the sensitivity between a spiral and a twin slot antenna coupled HEB mixer, we designed both types of mixers and fabricated them in a single processing run and on the same wafer. Both mixers have similar dimensions of NbN bridges (1.5-2 pm x0.2 pm). At 1.6 THz we obtained a nearly identical receiver noise temperature from both mixers (only 5% difference), which is in a good agreement with the simulation based on semi analytical models for both antennas. In addition, by using a bandpass filter to reduce the direct detection effect and lowering the bath temperature to 2.4 K, we measured the lowest receiver noise temperature of 700 K at 1.63 THz using the twin-slot antenna mixer.  
  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 1436  
Permanent link to this record
 
 
Author Gao, J. R.; Hajenius, M.; Tichelaar, F. D.; Voronov, B.; Grishina, E.; Klapwijk, T. M.; Gol'tsman, G.; Zorman, C. A. url  openurl
  Title Can NbN films on 3C-SiC/Si change the IF bandwidth of hot electron bolometer mixers? Type (up) Conference Article
  Year 2006 Publication Proc. 17th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 17th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 187-189  
  Keywords NbN HEB mixers  
  Abstract We realized ultra thin NbN films sputtered grown on a 3C-SiC/Si substrate. The film with a thickness of 3.5-4.5 nm shows a 1', of 11.8 K, which is the highest I`, observed among ultra thin NbN films on different substrates. The high-resolution transmission electron microscopy (HRTEM) studies show that the film has a monocrystalline structure, confirming the epitaxial growth on the 3C-SiC. Based on a two-temperature model and input parameters from standard NbN films on Si, simulations predict that the new film can increase the IF bandwidth of a HEB mixer by about a factor of 2 in comparison to the standard films. In addition, we find standard NbN films on Si with a T c of 9.4 K have a thickness of around 5.5 nm, being thicker than expected (3.5 nm).  
  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 1439  
Permanent link to this record
 
 
Author Gol'tsman, G.; Maslennikov, S.; Finkel, M.; Antipov, S.; Kaurova, N.; Grishina, E.; Polyakov, S.; Vachtomin, Y.; Svechnikov, S.; Smirnov, K.; Voronov, B. url  doi
openurl 
  Title Nanostructured ultrathin NbN film as a terahertz hot-electron bolometer mixer Type (up) Conference Article
  Year 2006 Publication Proc. MRS Abbreviated Journal Proc. MRS  
  Volume 935 Issue Pages 210 (1 to 6)  
  Keywords NbN HEB mixers  
  Abstract Planar spiral antenna coupled and directly lens coupled NbN HEB mixer structures are studied. An additional MgO buffer layer between the superconducting film and Si substrate is introduced. The buffer layer enables us to increase the gain bandwidth of a HEB mixer due to better acoustic transparency. The gain bandwidth is widened as NbN film thickness decreases and amounts to 5.2 GHz. The noise temperature of antenna coupled mixer is 1300 and 3100 K at 2.5 and 3.8 THz respectively. The structure and composition of NbN films is investigated by X-ray diffraction spectroscopy methods. Noise performance degradation at LO frequencies more than 3 THz is due to the use of a planar antenna and signal loss in contacts between the antenna and the sensitive NbN bridge. The mixer is reconfigured for operation at higher frequencies in a manner that receiver’s noise temperature is only 2300 K (3 times of quantum limit) at LO frequency of 30 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 0272-9172 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1440  
Permanent link to this record
 
 
Author Ryabchun, S.; Tong, C.-yu E.; Blundell, R.; Kimberk, R.; Gol’tsman, G. url  doi
openurl 
  Title Effect of microwave radiation on the stability of terahertz hot-electron bolometer mixers Type (up) Conference Article
  Year 2006 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 6373 Issue Pages 63730J (1 to 5)  
  Keywords NbN HEB mixers, hot-electron bolometer mixers, stability, Allan variance, LO power fluctuations  
  Abstract We report our studies of the effect of microwave radiation, with a frequency much lower than that corresponding to the energy gap of the superconductor, on the performance of the NbN hot-electron bolometer (HEB) mixer incorporated into a THz heterodyne receiver. It is shown that exposing the HEB mixer to microwave radiation does not result in a significant rise of the receiver noise temperature and degradation of the mixer conversion gain so long as the level of microwave power is small compared to the local oscillator drive. Hence the injection of a small, but controlled amount of microwave radiation enables active compensation of local oscillator power and coupling fluctuations which can significantly degrade the stability of HEB mixer receivers.  
  Address  
  Corporate Author Thesis  
  Publisher SPIE Place of Publication Editor Anwar, M.; DeMaria, A.J.; Shur, M.S.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference Terahertz Physics, Devices, and Systems  
  Notes Approved no  
  Call Number Serial 1441  
Permanent link to this record
 
 
Author Vachtomin, Y. B.; Antipov, S. V.; Maslennikov, S. N.; Smirnov, K. V.; Polyakov, S. L.; Zhang, W.; Svechnikov, S. I.; Kaurova, N. S.; Grishina, E. V.; Voronov, B. M.; Gol’tsman, G. N. url  doi
openurl 
  Title Quasioptical hot electron bolometer mixers based on thin NBN films for terahertz region Type (up) Conference Article
  Year 2006 Publication Proc. 16th Int. Crimean Microwave and Telecommunication Technology Abbreviated Journal Proc. 16th Int. Crimean Microwave and Telecommunication Technology  
  Volume 2 Issue Pages 688-689  
  Keywords NbN HEB mixers  
  Abstract Presented in this paper are the performances of HEB mixers based on 2-3.5 nm thick NbN films integrated with log-periodic spiral antenna. Double side-band receiver noise temperature values are 1300 K and 3100 K at 2.5 THz and at 3.8 THz, respectively. Mixer gain bandwidth is 5.2 GHz. Local oscillator power is 1-3 muW for mixers with different active area  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Russian 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 1445  
Permanent link to this record
 
 
Author Вахтомин, Ю. Б.; Антипов, С. В.; Масленников, С. Н.; Смирнов, К. В.; Поляков, С. Л.; Чжан, В.; Свечников, С. И.; Каурова, Н. С.; Гришина, Е. В.; Воронов, Б. М.; Гольцман, Г. Н. url  doi
openurl 
  Title Квазиоптические смесители терагерцового диапазона на основе эффекта разогрева электронов в тонких пленках NbN Type (up) Conference Article
  Year 2006 Publication Proc. 16th Int. Crimean Microwave and Telecommunication Technology Abbreviated Journal  
  Volume 2 Issue Pages 688-689  
  Keywords NbN HEB mixers  
  Abstract Представлены результаты измерения рактеристик смесителей на эффекте разогрева электронов в тонких сверхпроводниковых пленках NbN. Смесители были изготовлены на основе пленок NbN толщиной 2-3.5 нм осажденных на кремниевую подложку с буферным подсло- ем MgO. Смесительный элемент согласовывался с планар- ной логопериодической спиральной антенной. Лучшее зна- чение шумовой температуры приемника на основе NbN смесителя составило 1300 К и 3100 К на частотах гетеро- дина 2.5 TГц и 3.8 ТГц, соответственно. Максимальное зна- чение полосы преобразования, измеренной на частоте 900 |Ц, достигло значения 5.2 ГГц для смесителя изготовлен- ного из NbN пленки толщиной 2 нм. Оптимальная мощность Представлены результаты измерения ха- гетеродинного источника составила 1-3 мкВт для смесите- лей с различным объемом смесительного элемента.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Russian Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Duplicated as 1445 Approved no  
  Call Number Serial 1446  
Permanent link to this record
 
 
Author Zhang, W.; Jiang, L.; Lin, Z. H.; Yao, Q. J.; Li, J.; Shi, S. C.; Svechnikov, S. I.; Vachtomin, Yu. B.; Antipov, S. V.; Voronov, B. M.; Kaurova, N. S.; Gol'tsman, G. N. url  openurl
  Title Development of a quasi-optical NbN superconducting HEB mixer Type (up) Conference Article
  Year 2005 Publication Proc. 16th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 16th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 209-213  
  Keywords NbN HEB mixers  
  Abstract In this paper, we report the performance of a quasi-optical NbN superconducting HEB (hot electron bolometer) mixer measured at 500 and 850GHz. The quasi-optical NbN superconducting HEB mixer is cryogenically cooled by a 4-K close-cycled refrigerator. Measured receiver noise temperature at 850 and 500GHz are 3000K and 2500K respectively with wire grid as beamsplitter, while the lowest receiver noise temperature is found to be approximately 1200K with Mylar film. The theoretical receiver noise temperature (taking into account the elliptical polarization of log-spiral antenna) is consistent with measured one. The receiver noise temperature and conversion gain with 15-μm Mylar film as the beamsplitter at 500GHz are thoroughly investigated for different LO pumping levels and dc biases. The stability of the mixer’s IF output power is also demonstrated.  
  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 1470  
Permanent link to this record
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