%0 Journal Article
%T APEX Band T2: A 1.25 – 1.39 THz Waveguide  Balanced HEB Receiver
%A Meledin D.
%A Desmaris V.
%A Ferm S.-E.
%A Fredrixon M.
%A Henke D.
%A Lapkin I.
%A Nyström O.
%A Pantaleev M.
%A Pavolotsky A.
%A Strandberg M.
%A Sundin E.
%A Belitsky V.
%D 2008
%F MeledinD._etal2008
%O exported from refbase (https://db.rplab.ru/refbase/show.php?record=974), last updated on Mon, 06 Jul 2015 17:32:56 -0500
%X A waveguide 1.25–1.39 THz Hot Electron Bolometer (HEB) balanced receiver was successfully developed, characterized and installed at the Atacama Pathfinder EXperiment (APEX) telescope. The receiver employs a quadrature balanced scheme using a waveguide 90-degree 3 dB RF hybrid, HEB mixers and a 180-degree IF hybrid. The HEB mixers are based on ultrathin NbN film deposited on crystalline quartz with a MgO buffer layer. Integrated into the multi-channel APEX facility receiver (SHeFI), the results presented here demonstrate exceptional performance; a receiver  noise temperature of 1000 K measured at the telescope at the center of the receiver IF band 2-4 GHz, and at an LO frequency of 1294 GHz. Stability of the receiver is fully in line with the SIS mixer bands of the SHeFI, and gives a spectroscopic Allan time of more than 200 s with a noise bandwidth of 1 MHz.
%P 181-185