PT Unknown AU Wyss, RA Karasik, BS McGrath, WR Bamble, B LeDuc, H TI Noise and bandwidth measurements of diffusion–cooled Nb hot–electron bolometer mixers at frequencies above the superconductive energy gap SE Proc. 10[super:th] Int. Symp. Space Terahertz Technol. PY 1999 BP 215 EP 229 PI Charlottesville, Virginia ER