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Increased bandwidth of NbN phonon cooled hot electron bolometer mixers

Merlijn Hajenius, J. J. A. Baselmans, J. R. Gao +4 more

Softwaretechnik-TrendsJan 1, 20042 citations

NbN Phonon-Cooled Hot-Electron Bolometer Mixer with Additional Diffusion Cooling

Рябчун Сергей Александрович, Ivan V. Tretyakov, Matvey I. Finkel +5 more

Apr 1, 20093 citations

Mixer Performance Degradation Due to Contact Resistance in NbN Phonon-cooled Hot-electron Bolometers

H. Merke, P. Khosropanah, K. S. Yngvesson +4 more

Dec 1, 20010 citations

Improvement of Phonon Diffusion Efficiency in Phonon-Cooled NbN Hot Electron Bolometer Mixers

Shigehito Miki, Akira Kawakami, Yoshinori Uzawa +1 more

We propose a superconducting hot electron bolometer (HEB) mixer with an upper heat sink to improve the phonon diffusion efficiency in phonon cooled HEB mixers. We designed and fabricated NbN HEB mixers, and investigated the cooling effect of the upper heat sink by measuring intermediate frequency (IF) bandwidths of the HEB mixers. The SiO films for the upper dielectric heat sink, ranging in thickness from 9 to 35 µm, were deposited on the top of the NbN strip by high vacuum evaporation. We measured the IF bandwidths of HEB mixers, with and without the SiO heat sink, and observed that the 3-dB IF roll-off frequency increased from 0.4 to 0.7 GHz by using a 35-µm-thick SiO heat sink.We propose a superconducting hot electron bolometer (HEB) mixer with an upper heat sink to improve the phonon diffusion efficiency in phonon cooled HEB mixers. We designed and fabricated NbN HEB mixers, and investigated the cooling effect of the upper heat sink by measuring intermediate frequency (IF) bandwidths of the HEB mixers. The SiO films for the upper dielectric heat sink, ranging in thickness from 9 to 35 µm, were deposited on the top of the NbN strip by high vacuum evaporation. We measured the IF bandwidths of HEB mixers, with and without the SiO heat sink, and observed that the 3-dB IF roll-off frequency increased from 0.4 to 0.7 GHz by using a 35-µm-thick SiO heat sink.

Japanese Journal of Applied PhysicsJun 15, 20033 citations

NbN hot-electron bolometer mixers.

K. H. Gundlach, Thomas Lehnert, C. Rösch +4 more

Jan 1, 19980 citations

Low noise and wide bandwidth of NbN hot-electron bolometer mixers

Ivan V. Tretyakov, Рябчун Сергей Александрович, Matvey I. Finkel +5 more

We report a record double sideband noise temperature of 600 K (5hν/kB) offered by a NbN hot-electron bolometer receiver at 2.5 THz. Allowing for standing wave effects, this value was found to be constant in the intermediate frequency range 1–7 GHz, which indicates that the mixer has an unprecedentedly large noise bandwidth in excess of 7 GHz. The insight into this is provided by gain bandwidth measurements performed at the superconducting transition. They show that the dependence of the bandwidth on the mixer length follows the model for an HEB mixer with diffusion and phonon cooling of the hot electrons.We report a record double sideband noise temperature of 600 K (5hν/kB) offered by a NbN hot-electron bolometer receiver at 2.5 THz. Allowing for standing wave effects, this value was found to be constant in the intermediate frequency range 1–7 GHz, which indicates that the mixer has an unprecedentedly large noise bandwidth in excess of 7 GHz. The insight into this is provided by gain bandwidth measurements performed at the superconducting transition. They show that the dependence of the bandwidth on the mixer length follows the model for an HEB mixer with diffusion and phonon cooling of the hot electrons.

Applied Physics LettersJan 17, 201177 citations

Large Bandwidth Of Nbn Phonon-cooled Hot-electron Bolometer Mixers.

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Large Bandwidth Of Nbn Phonon-cooled Hot-electron Bolometer Mixers.

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