PT Journal
AU Baselmans, JJA
   Baryshev, A
   Reker, SF
   Hajenius, M
   Gao, JR
   Klapwijk, TM
   Vahtomin, Y
   Maslennikov, S
   Antipov, S
   Voronov, B
   Gol'tsman, G
TI Direct detection effect in small volume hot electron bolometer mixers
SO Appl. Phys. Lett.
JI Appl. Phys. Lett.
PY 2005
BP 163503 (1 to 3)
VL 86
IS 16
DI 10.1063/1.1887812
DE HEB; mixer; direct detection effect
AB We measure the direct detection effect in a small volume (0.15μm×1μm×3.5nm)(0.15μm×1μm×3.5nm) quasioptical NbN phonon cooled hot electronbolometermixer at 1.6THz1.6THz. We find that the small signal sensitivity of the receiver is underestimated by 35% due to the direct detection effect and that the optimal operating point is shifted to higher bias voltages when using calibration loads of 300K300K and 77K77K. Using a 200GHz200GHzbandpass filter at 4.2K4.2K the direct detection effect virtually disappears. This has important implications for the calibration procedure of these receivers in real telescope systems.
ER