TY - CONF AU - Gol'tsman, Gregory N. AU - Vachtomin, Yuriy B. AU - Antipov, Sergey V. AU - Finkel, Matvey I. AU - Maslennikov, Sergey N. AU - Smirnov, Konstantin V. AU - Polyakov, Stanislav L. AU - Svechnikov, Sergey I. AU - Kaurova, Natalia S. AU - Grishina, Elisaveta V. AU - Voronov, Boris M. A2 - Terahertz and Gigahertz Electronics and Photonics IV PY - 2005 DA - 2005// TI - NbN phonon-cooled hot-electron bolometer mixer for terahertz heterodyne receivers T2 - Proc. SPIE BT - Proc. SPIE SP - 95 EP - 106 VL - 5727 KW - NbN HEB mixers AB - We present the results of our studies of NbN phonon-cooled HEB mixers at terahertz frequencies. The mixers were fabricated from NbN film deposited on a high-resistivity Si substrate with an MgO buffer layer. The mixer element was integrated with a log-periodic spiral antenna. The noise temperature measurements were performed at 2.5 THz and at 3.8 THz local oscillator frequencies for the 3 x 0.2 μm2 active area devices. The best uncorrected receiver noise temperatures found for these frequencies are 1300 K and 3100 K, respectively. A water vapour discharge laser was used as the LO source. The largest gain bandwidth of 5.2 GHz was achieved for a mixer based on 2 nm thick NbN film deposited on MgO layer over Si substrate. The gain bandwidth of the mixer based on 3.5 nm NbN film deposited on Si with MgO is 4.2 GHz and the noise bandwidth for the same device amounts to 5 GHz. We also present the results of our research into decrease of the direct detection contribution to the measured Y-factor and a possible error of noise temperature calculation. The use of a square nickel cell mesh as an IR-filter enabled us to avoid the effect of direct detection and measure apparent value of the noise temperature which was 16% less than that obtained using conventional black polyethylene IR-filter. UR - https://doi.org/10.1117/12.590490 DO - 10.1117/12.590490 N1 - exported from refbase (https://db.rplab.ru/refbase/show.php?record=378), last updated on Mon, 17 May 2021 21:06:59 -0500 ID - Goltsman_etal2005 ER -