PT Journal
AU Meledin, D
   Pavolotsky, A
   Desmaris, V
   Lapkin, I
   Risacher, C
   Perez, V
   Henke, D
   Nystrom, O
   Sundin, E
   Dochev, D
   Pantaleev, M
   Fredrixon, M
   Strandberg, M
   Voronov, B
   Goltsman, G
   Belitsky, V
TI A 1.3-THz balanced waveguide HEB mixer for the APEX telescope
SO IEEE Trans. Microw. Theory Techn.
PY 2009
BP 89
EP 98
VL 57
IS 1
DI 10.1109/TMTT.2008.2008946
DE HEB; mixer; waveguide; balanced; NbN
AB In this paper, we report about the development, fabrication, and characterization of a balanced waveguide hot electron bolometer (HEB) receiver for the Atacama Pathfinder EXperiment telescope covering the frequency band of 1.25–1.39 THz. The receiver uses a quadrature balanced scheme and two HEB mixers, fabricated from 4- to 5-nm-thick NbN film deposited on crystalline quartz substrate with an MgO buffer layer in between. We employed a novel micromachining method to produce all-metal waveguide parts at submicrometer accuracy (the main-mode waveguide dimensions are 90×180 [mu]m). We present details on the mixer design and measurement results, including receiver noise performance, stability and “first-light” at the telescope site. The receiver yields a double-sideband noise temperature averaged over the RF band below 1200 K, and outstanding stability with a spectroscopic Allan time more than 200 s.
ER