PT Unknown
AU Ekström, H
   Kollberg, E
   Yagoubov, P
   Gol'tsman, G
   Gershenzon, E
   Yngvesson, S
TI Phonon cooled ultra thin NbN hot electron bolometer mixers at 620 GHz
SE Proc. 8[super:th] Int. Symp. Space Terahertz Technol.
PY 1997
BP 29
EP 35
DE NbN HEB mixers
AB We have measured the noise performance and gain bandwidth of 35 A thin NbN hot-electron mixers integrated with spiral antennas on silicon substrate lenses at 620 GHz. A double-sideband receiver noise temperature less than 1300 K has been obtained with a 3 dB bandwidth of GHz. The gain bandwidth is 3.2 GHz. A lower noise temperature of 1100 K has been achieved with an improved set-up. The mixer output noise dominated by thermal fluctuations is about 50-60 K, and the SSB receiver and intrinsic conversion gain is about -18 and -12 dB, respectively. Without mismatch losses and excluding the loss from the beamsplitter, we expect to achieve a receiver noise temperature of less than 700 K.
ER