Title :
Thermal time constant of Nb diffusion-cooled superconducting hot-electron bolometer mixers
Author :
Wilms Fleet, D. ; Gao, J.R. ; Klapwijk, T.M. ; de Eorte, P.A.J.
Author_Institution :
Dept. of Appl. Phys., Delft Univ. of Technol., Netherlands
fDate :
3/1/2001 12:00:00 AM
Abstract :
We present an experimental study of the intermediate frequency bandwidth of a Nb diffusion-cooled hot-electron bolometer mixer for different bias voltages. The measurements show that the bandwidth increases with increasing voltage. Analysis of the data reveals that this effect is mainly caused by a decrease of the intrinsic thermal time constant of the mixer and that the effect of electrothermal feedback through the intermediate frequency circuit is small. The results are understood using a qualitative model, which takes into account the different effective diffusion constants in the normal and superconducting domains
Keywords :
bolometers; niobium; submillimetre wave mixers; superconducting mixers; Nb; Nb diffusion-cooled superconducting hot-electron bolometer mixers; bias voltages; effective diffusion constants; electrothermal feedback; intermediate frequency bandwidth; intermediate frequency circuit; intrinsic thermal time constant; thermal time constant; Bandwidth; Bolometers; Cause effect analysis; Data analysis; Electrons; Frequency; Niobium; Space technology; Temperature dependence; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on