Title :
Development of THz Waveguide NbTiN HEB Mixers
Author :
Jiang, Ling ; Shiba, Shoichi ; Shimbo, Ken ; Sakai, Nami ; Yamakura, Tetsuya ; Sugimura, Mika ; Ananthasubramanian, P.G. ; Maezawa, Hiroyuki ; Irimajiri, Yoshihisa ; Yamamoto, Satoshi
Author_Institution :
Dept. of Phys., Univ. of Tokyo, Tokyo, Japan
fDate :
6/1/2009 12:00:00 AM
Abstract :
In this paper, we present the development of the waveguide niobium titanium nitride (NbTiN) superconducting hot electron bolometer (HEB) mixers, cryogenically cooled by a 4 K close-cycled refrigerator. The NbTiN thin film is formed on a crystalline quartz substrate by sputtering an NbTi target with the Ar and N2 gas at room temperature. The HEB mixer element is fabricated by using the 12 nm NbTiN film, and is mounted on a waveguide block. Measurement of a Fourier transform spectrometer shows that the response of the mixer is centered near 810 GHz with a bandwidth of about 500 GHz. The uncorrected DSB receiver noise temperature is measured to be 500 K, and the noise bandwidth is to be 1.4 GHz at 810 GHz. The present result shows that a good noise performance can be obtained for the NbTiN HEB mixer even with a relatively thick film (12 nm) fabricated at the room temperature.
Keywords :
Fourier transform spectroscopy; bolometers; cryogenics; hot carriers; niobium compounds; sputtering; submillimetre wave mixers; superconducting mixers; thin films; titanium compounds; Fourier transform spectrometer; NbTiN; THz waveguide HEB mixer; bandwidth 1.4 GHz; close-cycled refrigerator; crystalline quartz substrate; frequency 810 GHz; noise bandwidth; size 12 nm; superconducting hot electron bolometer mixer; temperature 293 K to 298 K; temperature 4 K; temperature 500 K; thin film; uncorrected DSB receiver noise temperature; Hot electron bolometer mixer; NbTiN film; Terahertz;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2009.2019071
