PT Journal
AU Floet D. W.
   Gao J. R.
   Klapwijk T. M.
   de Korte P. A. J.
TI Bias Dependence of the Thermal Time Constant in Nb Superconducting Diffusion-Cooled HEB Mixers
SO Appl. Phys. Lett.
JI Appl. Phys. Lett.
PY 2000
BP 1719
VL 77
DI 10.1063/1.1287909
AB 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 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.
ER