| Home | << 1 2 3 4 5 6 7 8 9 >> |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol'tsman, G. | ||||
| Title | Doubling of sensitivity and bandwidth in phonon cooled hot electron bolometer mixers | Type | Journal Article | ||
| Year | 2004 | Publication | Appl. Phys. Lett. | Abbreviated Journal | Appl. Phys. Lett. |
| Volume | 84 | Issue | 11 | Pages | 1958-1960 |
| Keywords | NbN HEB mixers | ||||
Abstract  |
We demonstrate that the performance of NbN lattice cooled hot electron bolometer mixers depends strongly on the interface quality between the bolometer and the contact structure. We show experimentally that both the receiver noise temperature and the gain bandwidth can be improved by more than a factor of 2 by cleaning the interface and adding an additional superconducting interlayer to the contact pad. Using this we obtain a double sideband receiver noise temperature TN,DSB=950 K at 2.5 THz and 4.3 K, uncorrected for losses in the optics. At the same bias point, we obtain an IF gain bandwidth of 6 GHz. |
||||
| 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 | 352 | |||
| Permanent link to this record | |||||
| Author | Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Baryshev, A.; Kooi, J.; Klapwijk, T. M.; Voronov, B.; de Korte, P.; Gol'tsman, G. | ||||
| Title | NbN hot electron bolometer mixers: sensitivity, LO power, direct detection and stability | Type | Journal Article | ||
| Year | 2005 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
| Volume | 15 | Issue | 2 | Pages | 484-489 |
| Keywords | HEB mixers, direct detection effect, stability, Allan variance | ||||
| Abstract |
We demonstrate that the performance of NbN lattice cooled hot electron bolometer mixers depends strongly on the interface quality between the bolometer and the contact structure. Both the receiver noise temperature and the gain bandwidth can be improved by a factor of 2 by cleaning the interface and adding an additional superconducting interlayer to the contact pad. Using this we obtain a double sideband receiver noise temperature of 950 K at 2.5 THz and 4.3 K, using a 0.4/spl times/4 /spl mu/m HEB mixer with a spiral antenna. At the same bias point, we obtain an IF gain bandwidth of 6 GHz. To comply with current demands on THz mixers for use in space based receivers we reduce the device size to 0.15/spl times/1 /spl mu/m and use a twin slot antenna. We report measurements of the noise temperature, LO power requirement, stability and the direct detection effect, using a mixer with a 1.6 THz twin slot antenna and a 1.462 THz solid state LO source with calibrated output power. | ||||
| 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 | 546 | |||
| 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. | ||||
| Title | Direct comparison of the sensitivity of a spiral and a twin-slot antenna coupled HEB mixer at 1.6 THz | Type | 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.; Klapwijk, T. M.; Voronov, B.; Grishin, E.; Gol’tsman, G.; Zorman, C. A.; Mehregany, M. | ||||
| Title | Monocrystalline NbN nanofilms on a 3C-SiC∕Si substrate | Type | Journal Article | ||
| Year | 2007 | Publication | Appl. Phys. Lett. | Abbreviated Journal | Appl. Phys. Lett. |
| Volume | 91 | Issue | 6 | Pages | 062504 (1 to 3) |
| Keywords | NbN films, nanofilms | ||||
| Abstract |
The authors have realized NbN (100) nanofilms on a 3C-SiC (100)/Si(100) substrate by dc reactive magnetron sputtering at 800°C. High-resolution transmission electron microscopy (HRTEM) is used to characterize the films, showing a monocrystalline structure and confirming epitaxial growth on the 3C-SiC layer. A film ranging in thickness from 3.4to4.1nm shows a superconducting transition temperature of 11.8K, which is the highest reported for NbN films of comparable thickness. The NbN nano-films on 3C-SiC offer a promising alternative to improve terahertz detectors. For comparison, NbN nanofilms grown directly on Si substrates are also studied by HRTEM. The authors acknowledge S. V. Svetchnikov at National Centre for HRTEM at Delft, who prepared the specimens for HRTEM inspections. This work was supported by the EU through RadioNet and INTAS. |
||||
| 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 | 0003-6951 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | Serial | 1425 | |||
| 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. | ||||
| 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 | |||||