PT Unknown AU Hübers, H Semenov, A Schubert, J Gol'tsman, G Voronov, B Gershenzon, E TI Performance of the phonon-cooled hot-electron bolometric mixer between 0.7 THz and 5.2 THz SE Proc. 8-th Int. Conf. on Terahertz Electronics PY 2000 BP 117 EP 119 DE NbN HEB mixers AB We report on the phonon cooled NbN hot electron bolometer as mixer in the terahertz frequency range. Its hybrid antenna consists of a hyperhemispheric silicon lens and a logarithmic-spiral feed antenna. Noise temperatures have been measured between 0.7 THz and 5.2 THz. A quarter wavelength layer of Parylene works as antireflection coating for the silicon lens and reduces the noise temperature by about 30. It was found that the antenna pattern at 2.5 THz is determined by the feed antenna and not by the diameter of the lens. ER