PT Unknown
AU Schubert, J
   Semenov, A
   Gol'tsman, G
   Hübers, H
   Schwaab, G
   Voronov, B
   Gershenzon, E
TI Noise temperature and sensitivity of a NbN hot-electron mixer at frequencies from 0.7 THz to 5.2 THz
SE Proc. 10[super:th] Int. Symp. Space Terahertz Technol.
PY 1999
BP 190
EP 199
DE NbN HEB mixers
AB We report on noise temperature measurements of a NbN phonon-cooled hot-electron bolometric mixer at different bias regimes. The device was a 3 nm thick bridge with in-plane dimensions of 1.7 x 0.2 gm 2 integrated in a complementary logarithmic spiral antenna. Measurements were performed at frequencies ranging from 0.7 THz up to 5.2 THz. The measured DSB noise temperatures are 1500 K (0.7 THz), 2200 K (1.4 THz), 2600 K (1.6 THz), 2900 K (2.5 THz), 4000 K (3.1 THz) 5600 K (4.3 THz) and 8800 K (5.2 THz). Two bias regimes are possible in order to achieve low noise temperatures. But only one of them yields sensitivity fluctuations close to the theoretical limit.
ER