Development of 1THz SIS mixer for SOFIA

Alexandre Karpov, David A. B. Miller, Jeff A. Stern, B. Bumble, Henry George LeDuc, Jonas Stasys Zmuidzinas

Published Jan 1, 2007• 3 citations

Abstract

We report the development of a low noise and broadband SIS mixer aimed for 1 THz channel of the Caltech Airborne Submillimeter Interstellar Medium Investigations Receiver (CASIMIR), designed for the Stratospheric Observatory for Far Infrared Astronomy, (SOFIA). In the SIS mixer are used the Nb/AlN/NbTiN junctions with the Josephson critical current density of about 40 KA/cm . The mixer is built using a double-slot quasi-optical design and covers a 250 GHz band centered at 1 THz. The minimum measured receiver noise is about 353 K (Y=1.50). The receiver noise may be reduced using a higher level of LO power. The developed mixer will allow building a receiver with the noise temperature approaching 250 K in 1 THz band and having a broader operation band compared to the previously reported.

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