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Author Ekström, H.; Karasik, B.; Kollberg, E.; Gol'tsman, G.; Gershenzon, E.
Title 350 GHz NbN hot electron bolometer mixer Type Conference Article
Year 1995 Publication Proc. 6th Int. Symp. Space Terahertz Technol. Abbreviated Journal (down) Proc. 6th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 269-283
Keywords NbN HEB mixers
Abstract Superconducting NbN hot-electron bolometer (HEB) mixer devices have been fabricated and measured at 350 GHz. The HEB is integrated with a double dipole antenna on an extended crystalline quartz hyper hemispherical substrate lens. Heterodyne measurement gave a -3 dB bandwidth, mainly determined by the electron- phonon interaction time, of about 680 and 1000 MHz for two different films with Tc = 8.5 and 11 K respectively. The measured DSB receiver noise temperature is around 3000 K at 800 MHz IF frequency. The main contribution to the output noise from the device is due to electron temperature fluctuations with the equivalent output noise temperature TFL-100 K. TH, has the same frequency dependence as the IF response. The contribution from Johnson noise is of the order of T. The RF coupling loss is estimated to be = 6 dB. The film with lower Tc, had an estimated intrinsic low-frequency conversion loss = 7 dB, while the other film had a conversion loss as high as 14 dB. The difference in intrinsic conversion loss is explained by less uniform absorption of radiation. Measurements of the small signal impedance shows a transition of the output impedance from the DC differential resistance Rd=dV/dI in the low frequency limit to the DC resistance R 0 =Uoff 0 in the bias point for frequencies above 3 GHz. We judge that the optimum shape of the IV-characteristic is more easily obtained at THz frequencies where the main restriction in performance should come from problems with the RF coupling.
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Publisher Place of Publication Editor
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1628
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Author Gerecht, E.; Musante, C. F.; Schuch, R.; Lutz, C. R.; Jr.; Yngvesson, K. S.; Mueller, E. R.; Waldivian, J.; Gol'tsman, G. N.; Voronov, B. M.; Gershenzon, E. M.
Title Hot electron detection and mixing experiments in NbN at 119 micrometer wavelength Type Conference Article
Year 1995 Publication Proc. 6th Int. Symp. Space Terahertz Technol. Abbreviated Journal (down) Proc. 6th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 284-293
Keywords NbN HEB mixers, detectors
Abstract We have performed preliminary experiments with the goal of demonstrating a Hot Electron Bolometric (HEB) mixer for a 119 micrometer wavelength (2.5 THz). We have chosen a NbN device of size 700 x 350 micrometers. This device can easily be coupled to a laser LO source, which is advantageous for performing a prototype experiment. The relatively large size of the device means that the LO power required is in the mW range; this power can be easily obtained from a THz laser source. We have measured the amount of laser power actually absorbed in the device, and from this have estimated the best optical coupling loss to be about 10 di . We are developing methods for improving the optical coupling further. Preliminary measurements of the response of the device to a chopped black-body have not yet resulted in a measured receiver noise temperature. We expect to be able to complete this measurement in the near future.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1629
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Author Semenov, A.; Richter, H.; Hübers, H.-W.; Smirnov, K.; Voronov, B.; Gol'tsman, G.
Title Development of terahertz superconducting hot-electron bolometer mixers Type Conference Article
Year 2003 Publication Proc. 6th European Conf. Appl. Supercond. Abbreviated Journal (down) Proc. 6th European Conf. Appl. Supercond.
Volume 181 Issue Pages 2960-2965
Keywords NbN HEB mixers
Abstract We present recent results of the development of phonon cooled hot-electron bolometric (HEB) mixers for airborne and balloon borne terahertz heterodyne receivers. Three iomportant issues have been addresses: the quality of NbN films the HEB mixers were made from, the spectral properties of the HEB mixers and the local oscillator power required for optical operation. Studies with an atomic force microscope indicate, that the performance of the HEB mixer might have been effected by the microstructure of the NbN film. Antenna gain and noise temperature were investigated at terahertz frequencies for a HEB embedded in either log-spiral or twin-slot feed antenna. Comparison suggests that at frequencies above 3 THz the spiral feed provides better overall performance. At 1.6 THz, a power of 2.5 µW was required from the local oscillator for optimal operation of the HEB mixer.
Address Sorrento, Italy
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 0750309814, 978-0750309813 Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1505
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Author Blundell, R.; Kawamura, J. H.; Tong, C. E.; Papa, D. C.; Hunter, T. R.; Gol’tsman, G. N.; Cherednichenko, S. I.; Voronov, B. M.; Gershenzon, E. M.
Title A hot-electron bolometer mixer receiver for the 680-830 GHz frequency range Type Conference Article
Year 1998 Publication Proc. 6-th Int. Conf. Terahertz Electron. Abbreviated Journal (down) Proc. 6-th Int. Conf. Terahertz Electron.
Volume Issue Pages 18-20
Keywords NbN HEB mixers
Abstract We describe a heterodyne receiver designed to operate in the partially transparent atmospheric windows centered on 680 and 830 GHz. The receiver incorporates a niobium nitride thin film, cooled to 4.2 K, as the phonon-cooled hot-electron mixer element. The double sideband receiver noise, measured over the frequency range 680-830 GHz, is typically 700-1300 K. The instantaneous output bandwidth of the receiver is 600 MHz. This receiver has recently been used at the SubMillimeter Telescope, jointly operated by the Steward Observatory and the Max Planck Institute for Radioastronomy, for observations of the neutral carbon and CO spectral lines at 810 GHz and at 806 and 691 GHz respectively. Laboratory measurements on a second mixer in the same test receiver have yielded extended high frequency performance to 1 THz.
Address Leeds, UK
Corporate Author Thesis
Publisher IEEE Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 0-7803-4903-2 Medium
Area Expedition Conference IEEE Sixth International Conference on Terahertz Electronics Proceedings. THZ 98. (Cat. No.98EX171)
Notes Approved no
Call Number Serial 1581
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Author Yagoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Schubert, J.; Hubers, H.-W.; Schwaab, G.; Gol’tsman, G.; Gershenzon, E.
Title Performance of NbN phonon-cooled hot-electron bolometric mixer at Terahertz frequencies Type Conference Article
Year 1998 Publication Proc. 6-th Int. Conf. Terahertz Electron. Abbreviated Journal (down) Proc. 6-th Int. Conf. Terahertz Electron.
Volume Issue Pages 149-152
Keywords NbN HEB mixers
Abstract The performance of a NbN based phonon-cooled Hot Electron Bolometric (HEB) quasioptical mixer is investigated in the 0.65-3.12 THz frequency range. The device is made from a 3 nm thick NbN film on high resistivity Si and integrated with a planar spiral antenna on the same substrate. The in-plane dimensions of the bolometer strip are 0.2/spl times/2 /spl mu/m. The results of the DSB noire temperature are: 1300 K at 650 GHz, 4700 K at 2.5 TBz and 10000 K at 3.12 THz. The RF bandwidth of the receiver is at least 2.5 THz. The amount of LO power absorbed in the bolometer is about 100 nW. The mixer is linear to within 1 dB compression up to the signal level 10 dB below that of the LO. The intrinsic single sideband conversion gain is measured to be -9 dB, the total conversion gain -14 dB.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference IEEE Sixth International Conference on Terahertz Electronics Proceedings. THZ 98. (Cat. No.98EX171)
Notes Approved no
Call Number Serial 1582
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