PT Journal
AU Baselmans, JJA
   Hajenius, M
   Gao, JR
   Klapwijk, TM
   de Korte, PAJ
   Voronov, B
   Gol'tsman, G
TI Doubling of sensitivity and bandwidth in phonon cooled hot electron bolometer mixers
SO Appl. Phys. Lett.
JI Appl. Phys. Lett.
PY 2004
BP 1958
EP 1960
VL 84
IS 11
DI 10.1063/1.1667012
DE NbN HEB mixers
AB We demonstrate that the performance of NbN lattice cooled hot electron bolometer mixers depends strongly on the interface quality between the bolometer and the contact structure. We show experimentally that both the receiver noise temperature and the gain bandwidth can be improved by more than a factor of 2 by cleaning the interface and adding an additional superconducting interlayer to the contact pad. Using this we obtain a double sideband receiver noise temperature TN,DSB=950 Kat 2.5 THz and 4.3 K, uncorrected for losses in the optics. At the same bias point, we obtain an IF gain bandwidth of 6 GHz.
ER