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Author Nagatsuma, T.; Hirata, A.; Royter, Y.; Shinagawa, M.; Furuta, T.; Ishibashi, T.; Ito, H.
Title (up) A 120-GHz integrated photonic transmitter Type Conference Article
Year 2000 Publication Proc. International topical meeting on microwave photonics (MWP 2000) Abbreviated Journal
Volume Issue Pages 225 - 228
Keywords THz, teraherts communications, terahertz communication channel, photodiode, transmitter
Abstract A photonics-based 120-GHz transmitter has been developed. A photodiode, a planar antenna and a silicon lens were integrated to form a compact millimeter-wave (MMW) emitter. The MMW signal emitted from the transmitter has been detected with a waveguide-mounted Schottky diode. The received power exceeded 100 μW, which is the highest value ever reported for photonic MMW transmitter at frequencies of >100 GHz
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Notes Approved no
Call Number Serial 595
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Author Khosropanah, P.; Merkel, H.; Yngvesson, S.; Adam, A.; Cherednichenko, S.; Kollberg, E.
Title (up) A distributed device model for phonon-cooled HEB mixers predicting IV characteristics, gain, noise and IF bandwidth Type Conference Article
Year 2000 Publication Proc. 11th Int. Symp. Space Terahertz Technol. Abbreviated Journal
Volume Issue Pages 474-488
Keywords HEB mixer numerical model, diffusion cooling channel, diffusion channel, distributed HEB model, distributed model
Abstract A distributed model for phonon-cooled superconductor hot electron bolometer (HEB) mixers is given, which is based on solving the one-dimensional heat balance equation for the electron temperature profile along the superconductor strip. In this model it is assumed that the LO power is absorbed uniformly along the bridge but the DC power absorption depends on the local resistivity and is thus not uniform. The electron temperature dependence of the resistivity is assumed to be continuous and has a Fermi form. These assumptions are used in setting up the non-linear heat balance equation, which is solved numerically for the electron temperature profile along the bolometer strip. Based on this profile the resistance of the device and the IV curves are calculated. The IV curves are in excellent agreement with measurement results. Using a small signal model the conversion gain of the mixer is obtained. The expressions for Johnson noise and thermal fluctuation noise are derived. The calculated results are in close agreement with measurements, provided that one of the parameters used is adjusted.
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Publisher Place of Publication University of Michigan, Ann Arbor, MI USA Editor
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 893
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Author Floet D. W.; Gao J. R.; Klapwijk T. M.; de Korte P. A. J.
Title (up) Bias Dependence of the Thermal Time Constant in Nb Superconducting Diffusion-Cooled HEB Mixers Type Journal Article
Year 2000 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 77 Issue Pages 1719
Keywords
Abstract We present an experimental study of the intermediate frequency bandwidth of a Nb diffusion-cooled hot-electron bolometer mixer for different bias voltages. The measurements show that the bandwidth increases with increasing voltage. Analysis of the data reveals that this effect is mainly caused by a decrease of the intrinsic thermal time of the mixer and that the effect of electrothermal feedback through the intermediate frequency circuit is small. The results are understood using a qualitative model, which takes into account the different effective diffusion constants in the normal and superconducting domains.
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Notes Approved no
Call Number RPLAB @ atomics90 @ Serial 971
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Author Semenov, A. D.; Hübers, H.-W.; Schubert, J.; Gol'tsman, G. N.; Elantiev, A. I.; Voronov, B. M.; Gershenzon, E. M.
Title (up) Design and performance of the lattice-cooled hot-electron terahertz mixer Type Journal Article
Year 2000 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.
Volume 88 Issue 11 Pages 6758-6767
Keywords HEB mixer, charge imbalance, HF current distribution
Abstract We present the measurements and the theoreticalmodel of the frequency-dependent noise temperature of a superconductor lattice-cooled hot-electron bolometer mixer in the terahertz frequency range. The increase of the noise temperature with frequency is a cumulative effect of the nonuniform distribution of the high-frequency current in the bolometer and the charge imbalance, which occurs at the edges of the normal domain and at the contacts with normal metal. We show that under optimal operation the fluctuation sensitivity of the mixer is determined by thermodynamic fluctuations of the noise power, whereas at small biases there appears additional noise, which is probably due to the flux flow. We propose the prescription of how to minimize the influence of the current distribution on the mixer performance.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 306
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Author Wright, E. L.; Reese, E. D.
Title (up) Detection of the cosmic infrared background at 2.2 and 3.5 microns using DIRBE observations Type Journal Article
Year 2000 Publication Astrophys. J. Abbreviated Journal
Volume 545 Issue 1 Pages 43-55
Keywords IR applications
Abstract
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Publisher Place of Publication Editor
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-637X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 486
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Author Sergeev, A.; Mitin, V.
Title (up) Electron-phonon interaction in disordered conductors: Static and vibrating scattering potentials Type Journal Article
Year 2000 Publication Phys. Rev. B. Abbreviated Journal Phys. Rev. B.
Volume 61 Issue 9 Pages 6041-6047
Keywords disordered conductors, scattering potential, electron-phonon interaction
Abstract Employing the Keldysh diagram technique, we calculate the electron-phonon energy relaxation rate in a conductor with the vibrating and static δ-correlated random electron-scattering potentials. If the scattering potential is completely dragged by phonons, this model yields the Schmid’s result for the inelastic electron-scattering rate τ−1e−ph. At low temperatures the effective interaction decreases due to disorder, and τ−1e−ph∝T4l (l is the electron mean-free path). In the presense of the static potential, quantum interference of numerous scattering processes drastically changes the effective electron-phonon interaction. In particular, at low temperatures the interaction increases, and τ−1e−ph∝T2/l. Along with an enhancement of the interaction, which is observed in disordered metallic films and semiconducting structures at low temperatures, the suggested model allows us to explain the strong sensitivity of the electron relaxation rate to the microscopic quality of a particular film.
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Publisher Place of Publication Editor
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 307
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Author Smirnov, K. V.; Ptitsina, N. G.; Vakhtomin, Y. B.; Verevkin, A. A.; Gol’tsman, G. N.; Gershenzon, E. M.
Title (up) Energy relaxation of two-dimensional electrons in the quantum Hall effect regime Type Journal Article
Year 2000 Publication JETP Lett. Abbreviated Journal JETP Lett.
Volume 71 Issue 1 Pages 31-34
Keywords 2DEG, GaAs/AlGaAs heterostructures
Abstract The mm-wave spectroscopy with high temporal resolution is used to measure the energy relaxation times τe of 2D electrons in GaAs/AlGaAs heterostructures in magnetic fields B=0–4 T under quasi-equilibrium conditions at T=4.2 K. With increasing B, a considerable increase in τe from 0.9 to 25 ns is observed. For high B and low values of the filling factor ν, the energy relaxation rate τ −1e oscillates. The depth of these oscillations and the positions of maxima depend on the filling factor ν. For ν>5, the relaxation rate τ −1e is maximum when the Fermi level lies in the region of the localized states between the Landau levels. For lower values of ν, the relaxation rate is maximum at half-integer values of τ −1e when the Fermi level is coincident with the Landau level. The characteristic features of the dependence τ −1e (B) are explained by different contributions of the intralevel and interlevel electron-phonon transitions to the process of the energy relaxation of 2D electrons.
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-3640 ISBN Medium
Area Expedition Conference
Notes http://jetpletters.ru/ps/899/article_13838.shtml (“Энергетическая релаксация двумерных электронов в области квантового эффекта Холла”) Approved no
Call Number Serial 1559
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Author Semenov, A. D.; Hübers, H.–W.; Schubert, J.; Gol'tsman, G. N.; Elantiev, A. I.; Voronov, B. M.; Gershenzon, E. M.
Title (up) Frequency dependent noise temperature of the lattice cooled hot-electron terahertz mixer Type Conference Article
Year 2000 Publication Proc. 11th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 11th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 39-48
Keywords NbN HEB mixers
Abstract We present the measurements and the theoretical model on the frequency dependent noise temperature of a lattice cooled hot electron bolometer (HEB) mixer in the terahertz frequency range. The experimentally observed increase of the noise temperature with frequency is a cumulative effect of the non-uniform distribution of the high frequency current in the bolometer and the charge imbalance, which occurs near the edges of the normal domain and contacts with normal metal. In addition, we present experimental results which show that the noise temperature of a HEB mixer can be reduced by about 30% due to a Parylene antireflection coating on the Silicon hyperhemispheric lens.
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Notes Approved no
Call Number Serial 305
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Author Cherednichenko, S.; Kroug, M.; Yagoubov, P.; Merkel, H.; Kollberg, E.; Yngvesson, K. S.; Voronov, B.; Gol’tsman, G.
Title (up) IF bandwidth of phonon cooled HEB mixers made from NbN films on MgO substrates Type Conference Article
Year 2000 Publication Proc. 11th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 11th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 219-227
Keywords NbN HEB mixers, cinversion gain bandwidth, IF bandwidth
Abstract An investigation of gain and noise bandwidth of phonon-cooled hot-electron bolometric (HEB) mixers is presented. The radiation coupling to the mixers is quasioptical through either a spiral or twin-slot antenna. A maximum gain bandwidth of 4.8 GHz is obtained for mixers based on a 3.5 nm thin NbN film with Tc= 10 K. The noise bandwidth is 5.6 GHz, at the moment limited by parasitic elements in the, device mount fixture. At 0.65 THz the DSB receiver noise temperature is 700-800 К in the IF band 1-2 GHz, and 1150-2700 К in the band 3.5-7 GHz.
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Notes Approved no
Call Number Serial 1557
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Author Hansen, Lene; Jørgensen, H.E.; Nørgaard-Nielsen, Hans Ulrik; Pedersen, Kenneth; Goudfrooij, P.; Linden-Vornle, M.J.D.
Title (up) ISO far-infrared observations of rich galaxy clusters III. Abell 2029, Abell 2052, Abell 2142 Type Journal Article
Year 2000 Publication Astron. Astrophys. Abbreviated Journal A&A
Volume 362 Issue 1 Pages 133-137
Keywords
Abstract A sample of five rich galaxy clusters has been mapped by ISO at 60 μm, 100 μm, 135 μm, and 200 μm using the PHT-C camera. In previous papers Abell 2670 and Sersic 159-03 were discussed. Here we present the results for Abell 2029, Abell 2052, and Abell 2142. The conclusion of the survey is that the relatively small fields (approximate to 60 square are minutes) are structured with filaments or superpositions of point sources. In some cases point sources (approximate to 0.1 Jy) can be identified with cluster galaxies. An attempt to demonstrate infrared emission from dust in the cooling flows (due to star formation) was inconclusive.
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Notes Approved no
Call Number RPLAB @ s @ Serial 456
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Author Gerecht, E.; Musante, C.F.; Zhuang, Y.; Ji, M.; Yngvesson, K.S.; Goyette, T.; Waldman, J.
Title (up) NbN hot electron bolometric mixer with intrinsic receiver noise temperature of less than five times the quantum noise limit Type Conference Article
Year 2000 Publication Proc. IMS Abbreviated Journal
Volume 2 Issue Pages 1007-1010
Keywords HEB mixer
Abstract In recent years, improvements in device development and quasi-optical coupling techniques utilizing planar antennas have led to a significant achievement in low noise receivers for the edges of the submillimeter frequency regime. Hot electron bolometric (HEB) receivers made of thin superconducting films such as NbN have produced a viable option for instruments designed to measure the molecular spectra for astronomical applications as well as in remote sensing of the atmosphere in the THz regime. This paper describes an NbN HEB mixer with intrinsic DSB receiver noise temperature of at most five times the quantum noise limit at frequencies as high as 2.24 THz
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Notes Approved no
Call Number Serial 477
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Author Huebers, H.-W.; Semenov, A.; Schubert, J.; Gol’tsman, G. N.; Voronov, B. M.; Gershenzon, E. M.; Krabbe, A.; Roeser, H.-P.
Title (up) NbN hot-electron bolometer as THz mixer for SOFIA Type Conference Article
Year 2000 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 4014 Issue Pages 195-202
Keywords NbN HEB mixers, airborne, stratospheric observatory, SOFIA
Abstract Heterodyne receivers for applications in astronomy need quantum limited sensitivity. We have investigated phonon- cooled NbN hot electron bolometric mixers in the frequency range from 0.7 THz to 5.2 THz. The devices were 3.5 nm thin films with an in-plane dimension of 1.7 X 0.2 micrometers 2 integrated in a complementary logarithmic spiral antenna. The best measured DSB receiver noise temperatures are 1300 K (0.7 THz), 2000 K (1.4 THz), 2100 K (1.6 THz), 2600 K (2.5 THz), 4000 K (3.1 THz), 5600 K (4.3 THz), and 8800 K (5.2 THz). The sensitivity fluctuation, the long term stability, and the antenna pattern were measured. The results demonstrate that this mixer is very well suited for GREAT, the German heterodyne receiver for SOFIA.
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Publisher SPIE Place of Publication Editor Melugin, R.K.; Roeser, H.-P.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Airborne Telescope Systems
Notes Approved no
Call Number Serial 1554
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Author Semenov, A. D.; Gol’tsman, G. N.
Title (up) Nonthermal mixing mechanism in a diffusion-cooled hot-electron detector Type Journal Article
Year 2000 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.
Volume 87 Issue 1 Pages 502-510
Keywords NbN HEB mixers, nonthermal
Abstract We present an analysis of a diffusion-cooled hot-electron detector fabricated from clean superconducting material with low transition temperature. The distinctive feature of a clean material, i.e., material with large electron mean free path, is a relatively weak inelastic electron scattering that is not sufficient for the establishment of an elevated thermodynamic electron temperature when the detector is subjected to irradiation. We propose an athermal model of a diffusion-cooled detector that relies on suppression of the superconducting energy gap by the actual dynamic distribution of excess quasiparticles. The resistive state of the device is caused by the electric field penetrating into the superconducting bridge from metal contacts. The dependence of the penetration length on the energy gap delivers the detection mechanism. The sources of the electric noise are equilibrium fluctuations of the number of thermal quasiparticles and frequency dependent shot noise. Using material parameters typical for A1, we evaluate performance of the device in the heterodyne regime at terahertz frequencies. Estimates show that the mixer may have a noise temperature of a few quantum limits and a bandwidth of a few tens of GHz, while the required local oscillator power is in the μW range due to ineffective suppression of the energy gap by quasiparticles with high energies.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1558
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Author Hübers, Heinz-Wilhelm; Semenov, Alexei; Schubert, Josef; Gol'tsman, Gregory; Voronov, Boris; Gershenzon, Evgeni
Title (up) Performance of the phonon-cooled hot-electron bolometric mixer between 0.7 THz and 5.2 THz Type Conference Article
Year 2000 Publication Proc. 8-th Int. Conf. on Terahertz Electronics Abbreviated Journal Proc. 8-th Int. Conf. on Terahertz Electronics
Volume Issue Pages 117-119
Keywords NbN HEB mixers
Abstract We report on the phonon cooled NbN hot electron bolometer as mixer in the terahertz frequency range. Its hybrid antenna consists of a hyperhemispheric silicon lens and a logarithmic-spiral feed antenna. Noise temperatures have been measured between 0.7 THz and 5.2 THz. A quarter wavelength layer of Parylene works as antireflection coating for the silicon lens and reduces the noise temperature by about 30. It was found that the antenna pattern at 2.5 THz is determined by the feed antenna and not by the diameter of the lens.
Address Darmstadt, Germany
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Area Expedition Conference International Conference on Terahertz Electronics [8th], Held inDarmstadt, Germany on 28-29 September 2000
Notes Approved no
Call Number Serial 1553
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Author Manus, M. K. Mc; Kash, J. A.; Steen, S. E.; Polonsky, S.; Tsang, J.C.; Knebel, D. R.; Huott, W.
Title (up) PICA: Backside failure analysis of CMOS circuits using picosecond imaging circuit analysis Type Journal Article
Year 2000 Publication Microelectronics Reliability Abbreviated Journal Microelectronics Reliability
Volume 40 Issue Pages 1353-1358
Keywords SSPD, CMOS testing
Abstract Normal operation of complementary metal-oxide semiconductor (CMOS) devices entails the emission of picosecond pulses of light, which can be used to diagnose circuit problems. The pulses that are observed from submicron sized field effect transistors (FETs) are synchronous with logic state switching. Picosecond Imaging Circuit Analysis (PICA), a new optical imaging technique combining imaging with timing, spatially resolves individual devices at the 0.5 micron level and switching events on a 10 picosecond timescale. PICA is used here for the diagnostics of failures on two VLSI microprocessors.
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Notes Approved no
Call Number Serial 1054
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