toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author (up) 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 (up) Hajenius, M.; Yang, Z. Q.; Gao, J. R.; Baselmans, J. J. A.; Klapwijk, T. M.; Voronov, B.; Gol'tsman, G. url  doi
openurl 
  Title Optimized sensitivity of NbN hot electron bolometer mixers by annealing Type Journal Article
  Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 17 Issue 2 Pages 399-402  
  Keywords NbN HEB mixers  
  Abstract We report that the heterodyne sensitivity of superconducting hot-electron bolometers (HEBs) increases by 25-30% after annealing at 85degC in high vacuum. The devices studied are twin-slot antenna coupled mixers with a small area NbN bridge of 1 mum times 0.15 mum, above which there is a SiO 2 passivation layer. The mixer noise temperature, gain, and resistance versus temperature curve of a HEB before and after annealing are compared and analysed. We show that the annealing reduces the intrinsic noise of the mixer by 37% and makes the superconducting transition of the bridge and the contacts sharper. We argue that the reduction ofthe noise is mainly due to the improvement of the transparency of the contact/film interface. The lowest receiver noise temperature of 700 K is measured at a local oscillator frequency of 1.63 THz and at a bath temperature of 4.2 K.  
  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 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1426  
Permanent link to this record
 

 
Author (up) Klapwijk, T. M.; Barends, R.; Gao, J. R.; Hajenius, M.; Baselmans, J. J. A. openurl 
  Title Improved superconducting hot-electron bolometer devices for the THz range Type Conference Article
  Year 2004 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 5498 Issue Pages 129-139  
  Keywords HEB mixer distributed model, numerical model  
  Abstract Improved and reproducible heterodyne mixing (noise temperatures of 950 K at 2.5 THz) has been realized with NbN based hot-electron superconducting devices with low contact resistances. A distributed temperature numerical model of the NbN bridge, based on a local electron and a phonon temperature, has been used to understand the physical conditions during the mixing process. We find that the mixing is predominantly due to the exponential rise of the local resistivity as a function of electron temperature.  
  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 Invited talk, Recommended by Klapwijk Approved no  
  Call Number Serial 912  
Permanent link to this record
 

 
Author (up) Kooi, J. W.; Baselmans, J. J. A.; Baryshev, A.; Schieder, R.; Hajenius, M.; Gao, J.R.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G. url  doi
openurl 
  Title Stability of heterodyne terahertz receivers Type Journal Article
  Year 2006 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.  
  Volume 100 Issue 6 Pages 064904 (1 to 9)  
  Keywords NbN HEB mixers  
  Abstract In this paper we discuss the stability of heterodyne terahertz receivers based on small volume NbN phonon cooled hot electron bolometers (HEBs). The stability of these receivers can be broken down in two parts: the intrinsic stability of the HEB mixer and the stability of the local oscillator (LO) signal injection scheme. Measurements show that the HEB mixer stability is limited by gain fluctuations with a 1∕f spectral distribution. In a 60MHz noise bandwidth this results in an Allan variance stability time of ∼0.3s. Measurement of the spectroscopic Allan variance between two intermediate frequency (IF) channels results in a much longer Allan variance stability time, i.e., 3s between a 2.5 and a 4.7GHz channel, and even longer for more closely spaced channels. This implies that the HEB mixer 1∕f noise is strongly correlated across the IF band and that the correlation gets stronger the closer the IF channels are spaced. In the second part of the paper we discuss atmospheric and mechanical system stability requirements on the LO-mixer cavity path length. We calculate the mixer output noise fluctuations as a result of small perturbations of the LO-mixer standing wave, and find very stringent mechanical and atmospheric tolerance requirements for receivers operating at terahertz frequencies.  
  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 0021-8979 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1444  
Permanent link to this record
 

 
Author (up) Kooi, J. W.; Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Dieleman, P.; Baryshev, A.; de Lange, G. url  doi
openurl 
  Title IF impedance and mixer gain of NbN hot electron bolometers Type Journal Article
  Year 2007 Publication J. Appl. Phys. Abbreviated Journal  
  Volume 101 Issue 4 Pages 044511  
  Keywords  
  Abstract  
  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 0021-8979 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number RPLAB @ s @ Serial 445  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: