PT Unknown
AU Hubers, H
   Semenov, A
   Richter, H
   Schwarz, M
   Gunther, B
   Smirnov, K
   Gol’tsman, G
   Voronov, B
TI Heterodyne receiver for 3-5 THz with hot-electron bolometer mixer
SE Proc. SPIE
PY 2004
BP 579
EP 586
VL 5498
DI 10.1117/12.552974
DE NbN HEB mixers
AB Heterodyne receivers for applications in astronomy and planetary research need quantum limited sensitivity. In instruments which are currently build for SOFIA and Herschel superconducting hot electron bolometers (HEB) will be used to achieve this goal at frequencies above 1.4 THz. The local oscillator and the mixer are the most critical components for a heterodyne receiver operating at 3-5 THz. The design and performance of an optically pumped THz gas laser optimized for this frequency band will be presented. In order to optimize the performance for this frequency hot electron bolometer mixers with different in-plane dimensions and logarithmic-spiral feed antennas have been investigated. Their noise temperatures and beam patterns were measured. Above 3 THz the best performance was achieved with a superconducting bridge of 2.0 x 0.2 μm[super:2] incorporated in a logarithmic spiral antenna. The DSB noise temperatures were 2700 K, 4700 K and 6400 K at 3.1 THz, 4.3 THz and 5.2 THz, respectively. The results demonstrate that the NbN HEB is very well suited as a mixer for THz heterodyne receivers up to at least 5 THz.
ER