| Records |
| Author |
Hajenius, M.; Baselmans, J. J. A.; Gao, J. R.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol'tsman, G. |
| Title |
Low noise NbN superconducting hot electron bolometer mixers at 1.9 and 2.5 THz |
Type |
Journal Article |
| Year |
2004 |
Publication |
Supercond. Sci. Technol. |
Abbreviated Journal |
Supercond. Sci. Technol. |
| Volume |
17 |
Issue |
5 |
Pages |
S224-S228 |
| Keywords |
NbN HEB mixers |
| Abstract |
NbN phonon-cooled hot electron bolometer mixers (HEBs) have been realized with negligible contact resistance between the bolometer itself and the contact structure. Using a combination of in situ cleaning of the NbN film and the use of an additional superconducting interlayer of a 10 nm NbTiN layer between the Au of the contact structure and the NbN film superior noise temperatures have been obtained as low as 950 K at 2.5 THz and 750 K at 1.9 THz. Here we address in detail the DC characterization of these devices, the interface transparencies between the bolometers and the contacts and the consequences of these factors on the mixer performance. |
| 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 |
0953-2048 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
|
Serial  |
558 |
| Permanent link to this record |
| |
|
| |
| Author |
Siddiqi, I.; Prober, D. E. |
| Title |
Nb–Au bilayer hot-electron bolometers for low-noise THz heterodyne detection |
Type |
Journal Article |
| Year |
2004 |
Publication |
Applied Physics Letters |
Abbreviated Journal |
Appl. Phys. Lett. |
| Volume |
84 |
Issue |
8 |
Pages |
1404 |
| Keywords |
HEB, mixers, dynamic range, saturation, LO power, local oscillator power, Nb |
| Abstract |
The sensitivity of present Nb diffusion-cooled hot-electron bolometer (HEB) mixers is not quantum limited, and can be improved by reducing the superconducting transition temperature TC. Lowering TC reduces thermal fluctuations, resulting in a decrease of the mixer noise temperature TM. However, lower TC mixers have reduced dynamic range and saturate more easily due to background noise. We present 30 GHz microwave measurements on a bilayer HEB system, Nb–Au, in which TC can be tuned with Au layer thickness to obtain the maximum sensitivity for a given noise background. These measurements are intended as a guide for the optimization of THz mixers. Using a Nb–Au mixer with TC = 1.6 K, we obtain TM = 50 K with 2 nW of local oscillator (LO) power. Good mixer performance is observed over a wide range of LO power and bias voltage and such a device should not exhibit saturation in a THz receiver. |
| 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 |
571 |
| Permanent link to this record |
| |
|
| |
| Author |
Klaassen, T. O.; Hovenier, J. N.; Adam, A. J. L.; Fischer, J.; Jakob, G.; Poglitsch, A.; Redlich, B. |
| Title |
Terahertz calorimetry for the Herschel Space Observatory |
Type |
Conference Article |
| Year |
2004 |
Publication |
Proc. 29th IRMMW / 12th THz |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
815-816 |
| Keywords |
mirror, reflection index, emissivity, calorimetry, space observatory, terahertz, THz |
| 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 |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
|
Serial |
578 |
| Permanent link to this record |
| |
|
| |
| Author |
van't Klooster, K.; Myasnikova, S. E.; Parshin, V. V.; Kasparek, W. |
| Title |
Results of reflection loss measurements of sample material for radio astronomy telescope antenna for Planck Project |
Type |
Conference Article |
| Year |
2004 |
Publication |
Proc. 14th international crimean conference on microwave and telecommunication technology |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
753-755 |
| Keywords |
mirror, reflection index, emissivity, Fabry-Perot interferometer, space observatory, terahertz, THz |
| Abstract |
Advanced radio telescope antennas for space applications are realised by the use of stable composite materials, which are lighter in general than various metal realisations. Reflectivity measurements have been carried out on high technology samples for the Planck radio telescope. Highly accurate results have been obtained at the Applied Physics Institute in Nizhny Novgorod, and an independent measurement with a totally different setup at the University of Stuttgart confirmed that one of the samples showed a strange behaviour. Moreover, it confirmed the high accuracy of the testing method. |
| 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 |
579 |
| Permanent link to this record |
| |
|
| |
| Author |
González, Francisco Javier; Alda, Javier; Ilic, Bojan; Boreman, Glenn D. |
| Title |
Infrared Antennas Coupled to Lithographic Fresnel Zone Plate Lenses |
Type |
Journal Article |
| Year |
2004 |
Publication |
Applied Optics |
Abbreviated Journal |
Appl. Opt. |
| Volume |
43 |
Issue |
33 |
Pages |
6067-6073 |
| Keywords |
optical antennas |
| Abstract |
Several designs for Fresnel zone plate lenses (FZPLs) to be used in conjunction with antenna-coupled infrared detectors have been fabricated and tested. The designs comprise square and circular FZPLs with different numbers of Fresnel zones working in transmissive or reflective modes designed to focus infrared energy on a square-spiral antenna connected to a microbolometer. A 163× maximum increase in response was obtained from a 15-zone circular FZPL in the transmissive mode. Sensor measurements of normalized detectivity D* resulted in a 2.67× increase with FZPLs compared with measurements made of square-spiral antennas without FZPLs. The experimental results are discussed and compared with values obtained from theoretical calculations. |
| 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 |
RPLAB @ gujma @ |
Serial |
740 |
| Permanent link to this record |
