TY  - CONF
AU  - Baselmans, J. J. A.
AU  - Hajenius, M.
AU  - Gao, J.
AU  - de Korte, P.
AU  - Klapwijk, T. M.
AU  - Voronov, B.
AU  - Gol’tsman, G.
A2  - Millimeter and Submillimeter Detectors for Astronomy II
ED  - Zmuidzinas, J.
ED  - Holland, W. S.
ED  - Withington, S.
PY  - 2004
DA  - 2004//
TI  - Doubling of sensitivity and bandwidth in phonon-cooled hot-electron bolometer mixers
T2  - Proc. SPIE
BT  - Proc. SPIE
SP  - 168
EP  - 176
VL  - 5498
PB  - SPIE
KW  - Hot electron bolometers
KW  - bandwidth
KW  - noise temperature
KW  - experimental
AB  - NbN hot electron bolometer (HEB) mixers are at this moment the best heterodyne detectors 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. This results in a contact resistance between the NbN bolometer and the contact pad. We compare identical bolometers, with different NbN - contact pad interfaces, coupled with a spiral antenna. We find that cleaning the NbN interface and adding a thin additional superconductor prior to the gold contact deposition improves the noise temperature and the bandwidth of the HEB mixers with more than a factor of 2. We obtain a DSB noise temperature of 950 K at 2.5 THz and a Gain bandwidth of 5-6 GHz. For use in real receiver systems we design small volume (0.15x1 micron) HEB mixers with a twin slot antenna. We find that these mixers combine good sensitivity (900 K at 1.6 THz) with low LO power requirement, which is 160 - 240 nW at the Si lens of the mixer. This value is larger than expected from the isothermal technique and the known losses in the lens by a factor of 3-3.5.
UR  - https://doi.org/10.1117/12.552547
DO  - 10.1117/12.552547
N1  - exported from refbase (https://db.rplab.ru/refbase/show.php?record=1744), last updated on Sun, 30 May 2021 14:17:46 -0500
ID  - Baselmans_etal2004
ER  -