Diffusion-Cooled Tantalum Hot-Electron Bolometer Mixers

A batch of experimental diffusion-cooled hot-electron bolometers (HEBs), suitable for use as mixers having input frequencies in the terahertz range and output frequencies up to about a gigahertz, exploit the superconducting/normal-conducting transition in a thin strip of tantalum. The design and operation of these HEB mixers are based on mostly the same principles as those of a prior HEB mixer that exploited the superconducting/ normal-conducting transition in a thin strip of niobium and that was described in "Diffusion-Cooled Hot-Electron Bolometer Mixer" (NPO-19719), NASA Tech Briefs, Vol. 21, No. 1 (January 1997), page 12a.