Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Hot-electron superconductive mixers for THz frequencies

William R. McGrath, Boris S. Karasik, Anders J. Skalare, Rolf A. Wyss, B. Bumble, Henry George LeDuc

Published Apr 29, 1999• 9 citations

Abstract

Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range from 1.1 THz to 2.5 THz. The mixer device employs diffusion as a cooling mechanism for hot electrons. The double sideband receiver noise temperature was measured to be approximately equals 2750 K at 2.5 K at 2.5 THz; and mixer IF bandwidths as high as 9 GHz are achieved for 0.1 micrometers long devices. The local oscillator power dissipated in the HEB microbridge was in the range 20- 100 nW. Further reductions in LO power and mixer noise can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated. A distributed-temperature model has been developed to properly describe the operation of the diffusion-cooled HEB mixer. The HEB mixer is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies.

DOI: 10.1117/12.347111

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