Broadband metamaterial receiver with cold-electron bolometers

A metamaterial receiver, featuring a 19-ring facet structure and intended for usage with a lens, has been successfully designed, fabricated, and tested. The presented concept uses cold-electron bolometers (CEBs) as sensing elements, which enables the design of multiabsorber receivers maintaining a balance between power load and noise. The micrometric size of the CEBs eliminates the need for microwave feed lines, facilitating integration within antenna slots. Using a ${\mathrm{YB}\mathrm{a}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}x}\phantom{\rule{0.2em}{0ex}}(\mathrm{YB}\mathrm{CO})$ Josephson junction oscillator, it is demonstrated that the CEB metamaterial receiver has broadband response, approaching 400 GHz, in two frequency bands: 0.15--0.55 and 0.9--1.3 THz. Additionally, the photon-noise-limited operation of the CEB metamaterial, operating at 0.3 K, is shown.