PT Unknown AU Goltsman, GN Vachtomin, YB Antipov, SV Finkel, MI Maslennikov, SN Polyakov, SL Svechnikov, SI Kaurova, NS Grishina, EV Voronov, BM TI Low-noise NbN phonon-cooled hot-electron bolometer mixers for terahertz heterodyne receivers SE Proc. 9-th WMSCI PY 2005 BP 154 EP 159 VL 9 DE NbN HEB mixers ER