Low noise in a diffusion-cooled hot-electron mixer at 2.5 THz

作者：Boris S. Karasik, Michael C. Gaidis, William R. McGrath, B. Bumble, Henry George LeDuc · 发表于：Applied Physics Letters · 年份：1997 · DOI：10.1063/1.119967 · 被引用次数：80 · 研究领域：Superconducting and THz Device Technology、Physics of Superconductivity and Magnetism、Thermal Radiation and Cooling Technologies

The noise performance of a Nb hot-electron bolometer mixer at 2.5 THz has been investigated. The devices are fabricated from a 12-nm-thick Nb film, and have a 0.30 μm×0.15 μm in-plane size, thus exploiting diffusion as the electron cooling mechanism. The rf coupling was provided by a twin-slot planar antenna on an elliptical Si lens. The experimentally measured double sideband noise temperature of the receiver was as low as 2750±250 K with an estimated mixer noise temperature of ≈900 K. The mixer bandwidth derived from both noise bandwidth and IF impedance measurements was ≈1.4 GHz. These results demonstrate the low-noise operation of the diffusion-cooled bolometer mixer above 2 THz.