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Low Noise 1 THz–1.4 THz Mixers Using Nb/Al-AlN/NbTiN SIS Junctions

Karpov, A. and Miller, D. and Rice, F. and Stern, J. A. and Bumble, B. and LeDuc, H. G. and Zmuidzinas, J. (2007) Low Noise 1 THz–1.4 THz Mixers Using Nb/Al-AlN/NbTiN SIS Junctions. IEEE Transactions on Applied Superconductivity, 17 (2, pt.). pp. 343-346. ISSN 1051-8223. doi:10.1109/TASC.2007.898277.

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We present the development of a low noise 1.2 THz and 1.4 THz SIS mixers for heterodyne spectrometry on the Stratospheric Observatory For Infrared Astronomy (SOFIA) and Herschel Space Observatory. This frequency range is above the limit for the commonly used Nb quasi particle SIS junctions, and a special type of hybrid Nb/AlN/NbTiN junctions has been developed for this project.We are using a quasi-optical mixer design with two Nb/AlN/NbTiN junctions with an area of 0.25 µm^2. The SIS junction tuning circuit is made of Nb and gold wire layers. At 1.13 THz the minimum SIS receiver uncorrected noise temperature is 450 K. The SIS receiver noise corrected for the loss in the LO coupler and in the cryostat optics is 350–450 K across 1.1–1.25 THz band. The receiver has a uniform sensitivity in a full 4–8 GHz IF band. The 1.4 THz SIS receiver test at 1.33–1.35 THz gives promising results, although limited by the level of available LO power. Extrapolation of the data obtained with low LO power level shows a possibility to reach 500 K DSB receiver noise using already existing SIS mixer.

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Additional Information:© Copyright 2007 IEEE. Reprinted with permission. Manuscript received August 29, 2006. [Posted online: 2007-07-23] The authors would like to thank T.W. Crowe and S.H. Jones from VIRGINIA DIODES INC for the loan of a 1.35 THz LO source.
Subject Keywords:Niobium alloys, radio astronomy, satellite applications, submillimeter wave receivers, THz technology, superconductor-insulator-superconductor mixers
Issue or Number:2, pt.
Record Number:CaltechAUTHORS:KARieeetas07
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:8919
Deposited By: Archive Administrator
Deposited On:01 Oct 2007
Last Modified:08 Nov 2021 20:54

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