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Author Loudkov, D. ♦ Tong, C.-Y.E. ♦ Blundell, R. ♦ Megerian, K.G. ♦ Stern, J.A.
Sponsorship Council on Superconductivity ♦ Appl. Superconductivity Conference Inc ♦ MIT
Source IEEE Xplore Digital Library
Content type Text
Publisher Institute of Electrical and Electronics Engineers, Inc. (IEEE)
File Format PDF
Copyright Year ©2002
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics ♦ Electricity & electronics ♦ Technology ♦ Engineering & allied operations ♦ Applied physics
Subject Keyword Electrons ♦ Bolometers ♦ Buffer layers ♦ Noise measurement ♦ Bandwidth ♦ Frequency measurement ♦ Electrical resistance measurement ♦ Temperature distribution ♦ Crystallization ♦ Substrates ♦ waveguide terahertz receiver ♦ Hot electron bolometric mixer ♦ NbTiN superconducting film
Abstract We present recent measurements of receiver noise temperature and intermediate frequency (IF) bandwidth in the frequency range 0.8-1.3 THz for waveguide NbTiN HEB mixers of various dimensions. These devices are fabricated from an NbTiN film deposited on crystalline quartz substrates with AlN buffer layer. The lengths of the mixer elements vary from 0.3 to 0.5 /spl mu/m and their widths vary from 3 to 10 /spl mu/m. Critical temperatures are typically at 8.5 K, and the measured normal state resistance of the devices is about 1000 ohms per square. All the device DC parameters demonstrate a high degree of uniformity. A double side band noise temperature at 0.8 THz as low as 550 K has been measured at an IF frequency of 1.8 GHz, with a conversion loss of around 14 dB. At an IF of 3 GHz, the noise temperature increases to 750 K. We have also made extensive measurements of the IF bandwidth as a function of bias voltages and currents. At the optimal low-noise operation point, a 3-dB IF bandwidth of 1.2 GHz is obtained for a wide variety of device dimensions and bath temperature.
Description Author affiliation :: Harvard-Smithsonian Center for Astrophys., Cambridge, MA, USA
ISSN 10518223
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2005-06-01
Publisher Place U.S.A.
Rights Holder Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Volume Number 15
Issue Number 2
Size (in Bytes) 121.26 kB
Page Count 4
Starting Page 476
Ending Page 479


Source: IEEE Xplore Digital Library