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Author Tong, C. Edward; Trifonov, Andrey; Blundell, Raymond; Shurakov, Alexander; Gol’tsman, Gregory
Title A digital terahertz power meter based on an NbN thin film Type Abstract
Year 2014 Publication Proc. 25th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 25th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (down) 170
Keywords waveguide NbN HEB mixers
Abstract We have further studied the effect of subjecting a superconducting Hot Electron Bolometer (HEB) element made from an NbN thin film to microwave radiation. Since the photon energy is weak, the microwave radiation does not simply heat the film, but generates a bi-static state, switching between the superconducting and normal states, upon the application of a small voltage bias. Indeed, a relaxation oscillation of a few MHz has previously been reported in this regime [1]. Switching between the superconducting and normal states modulates the reflected microwave pump power from the device. A simple homodyne setup readily recovers the spontaneous switching waveform in the time domain. The switching frequency is a function of both the bias voltage (DC heating) and the applied microwave power. In this work, we use a 0.8 THz HEB waveguide mixer for the purpose of demonstration. The applied microwave pump, coupled through a directional coupler, is at 1 GHz. Since the pump power is of the order of a few μW, a room temperature amplifier is sufficient to amplify the reflected pump power from the HEB mixer, which beats with the microwave source in a homodyne set-up. After further amplification, the switching waveform is passed onto a frequency counter. The typical frequency of the switching pulses is 3-5 MHz. It is found that the digital frequency count increases with higher microwave pump power. When the HEB mixer is subjected to additional optical power at 0.8 THz, the frequency count also increases. When we vary the incident optical power by using a wire grid attenuator, a linear relationship is observed between the frequency count and the applied optical power, over at least an order of magnitude of power. This phenomenon can be exploited to develop a digital power meter, using a very simple electronics setup. Further experiments are under way to determine the range of linearity and the accuracy of calibration transfer from the microwave to the THz regime. References 1. Y. Zhuang, and S. Yngvesson, “Detection and interpretation of bistatic effects in NbN HEB devices,” Proc. 13 th Int. Symp. Space THz Tech., 2002, pp. 463–472.
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Call Number Serial 1366
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Author Semenov, A. D.; Hübers, Heinz-Wilhelm; Richter, H.; Birk, M.; Krocka, M.; Mair, U.; Vachtomin, Yu. B.; Finkel, M. I.; Antipov, S. V.; Voronov, B. M.; Smirnov, K. V.; Kaurova, N. S.; Drakinski, V. N.; Gol'tsman, G. N.
Title Superconducting hot-electron bolometer mixer for terahertz heterodyne receivers Type Journal Article
Year 2003 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal
Volume 13 Issue 2 Pages (down) 168-171
Keywords NbN HEB mixers
Abstract We present recent results showing the development of superconducting NbN hot-electron bolometer mixer for German receiver for astronomy at terahertz frequencies and terahertz limb sounder. The mixer is incorporated into a planar feed antenna, which has either logarithmic spiral or double-slot configuration, and backed on a silicon lens. The hybrid antenna had almost frequency independent and symmetric radiation pattern slightly broader than expected for a diffraction limited antenna. At 2.5 THz the best 2200 K double side-band receiver noise temperature was achieved across a 1 GHz intermediate frequency bandwidth centred at 1.5 GHz. For this operation regime, a receiver conversion efficiency of -17 dB was directly measured and the loss budget was evaluated. The mixer response was linear at load temperatures smaller than 400 K. Implementation of the MgO buffer layer on Si resulted in an increased 5.2 GHz gain bandwidth. The receiver was tested in the laboratory environment by measuring a methanol emission line at 2.5 THz.
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Call Number Serial 343
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Author Semenov, Alexei D.; Hübers, Heinz-Wilhelm; Richter, Heiko; Smirnov, Konstantin; Gol'tsman, Gregory N.; Voronov, Boris M.
Title Superconducting hot-electron bolometer mixer for terahertz heterodyne receivers Type Abstract
Year 2004 Publication Proc. 15th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 15th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (down) 164
Keywords NbN HEB mixers
Abstract A number of on-going astronomical and atmospheric research programs are aimed to the Terahertz (THz) spectral region. At frequencies above about 1.4 THz heterodyne receivers planned for these missions will use superconducting hot-electron bolometers as a mixers. We present current results on the development of superconducting NbN hot- electron bolometer mixer and quasioptical radiation coupling scheme for GREAT (German Receiver for Astronomy at Terahertz Frequencies, to be used aboard of SOFIA) and TELIS (Terahertz Limb Sounder). The mixer is incorporated into hybrid antenna consisting of a planar feed antenna, which has either logarithmic spiral or double-slot configuration, and hyperhemispherical silicon lens. For the log-spiral feed antenna, the double side-band receiver noise temperature of 5500 K was achieved at 4.3 THz. The noise temperature shows less than 3 dB increase in the intermediate frequency band from 4 GHz to 7 GHz. The hybrid antenna had almost frequency independent and symmetric radiation pattern with the beam-width slightly broader than expected for a diffraction limited pattern. Results of FTS measurements in the direct detection regime agreed with the spectral dependence of the noise temperature for spiral antennas with different spacing of inner terminals.
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Call Number Serial 1492
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Author Goltsman, Gregory N.; Vachtomin, Yuriy B.; Antipov, Sergey V.; Finkel, Matvey I.; Maslennikov, Sergey N.; Polyakov, Stanislav L.; Svechnikov, Sergey I.; Kaurova, Natalia S.; Grishina, Elisaveta V.; Voronov, Boris M.
Title Low-noise NbN phonon-cooled hot-electron bolometer mixers for terahertz heterodyne receivers Type Conference Article
Year 2005 Publication Proc. 9-th WMSCI Abbreviated Journal Proc. 9-th WMSCI
Volume 9 Issue Pages (down) 154-159
Keywords NbN HEB mixers
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Publisher International Institute of Informatics and Systemics Place of Publication Editor
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Call Number Serial 547
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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 Proc. 6-th Int. Conf. Terahertz Electron.
Volume Issue Pages (down) 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.
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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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Author Gao, J. R.; Hajenius, M.; Baselmans, J. J. A.; Yang, Z. Q.; Baryshev, A. M.; Barends, R.; Klapwijk, T. M.; Voronov, B.; Gol'tsman, G.; Callaos, N.
Title Twin-slot antenna coupled NbN hot electron bolometer mixers for space applications Type Conference Article
Year 2005 Publication Proc. 9-th WMSCI Abbreviated Journal Proc. 9-th WMSCI
Volume 9 Issue Pages (down) 148-153
Keywords NbN HEB mixers
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Publisher International Institute of Informatics and Systemics Place of Publication Editor
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ISSN ISBN 9806560639, 9789806560635 Medium
Area Expedition Conference 9th World Multi-Conference on Systemics, Cybernetics and Informatics
Notes Approved no
Call Number Serial 1480
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Author Antipov, S.; Trifonov, A.; Krause, S.; Meledin, D.; Desmaris, V.; Belitsky, V.; Gol’tsman, G.
Title Gain bandwidth of NbN HEB mixers on GaN buffer layer operating at 2 THz local oscillator frequency Type Conference Article
Year 2017 Publication Proc. 28th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 28th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (down) 147-148
Keywords NbN HEB mixers, GaN buffer-layer, IF bandwidth
Abstract In this paper, we present IF bandwidth measurement results of NbN HEB mixers, which are employing NbN thin films grown on a GaN buffer-layer. The HEB mixers were operated in the heterodyne regime at a bath temperature of approximately 4.5 K and with a local oscillator operating at a frequency of 2 THz. A quantum cascade laser served as the local oscillator and a reference synthesizer based on a BWO generator (130-160 GHz) and a semiconductor superlattice (SSL) frequency multiplier was used as a signal source. By changing the LO frequency it was possible to record the IF response or gain bandwidth of the HEB with a spectrum analyzer at the operation point, which yielded lowest noise temperature. The gain bandwidth that was recorded in the heterodyne regime at 2 THz amounts to approximately 5 GHz and coincides well with a measurement that has been performed at elevated bath temperatures and lower LO frequency of 140 GHz. These findings strongly support that by using a GaN buffer-layer the phonon escape time of NbN HEBs can be significantly lower as compared to e.g. Si substrate, thus, providing higher gain bandwidth.
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Notes Approved no
Call Number Serial 1175
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Author Yazoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Gol'tsman, G.; Lipatov, A.; Svechnikov, S.; Gershenzon, E.
Title Quasioptical NbN phonon-cooled hot electron bolometric mixers with low optimal local oscillator power Type Conference Article
Year 1998 Publication Proc. 9th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 9th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (down) 131-140
Keywords NbN HEB mixers
Abstract In this paper, the noise perform.ance of NIN based phonon-cooled Hot Electron Bolometric (HEB) quasioptical mixers is investigated in the 0.55-1.1 THz frequency range. The best results of the DSB noise temperature are: 500 K at 640 GHz, 600 K at 750 GHz, 850 K at 910 GHz and 1250 K at 1.1 THz. The water vapor in the signal path causes a significant contribution to the measured noise temperature around 1.1 THz. The required LO power is typically about 60 nW. The frequency response of the spiral antenna+lens system is measured using a Fourier Transform Spectrometer with the HEB operating in a detector mode.
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Call Number Serial 1589
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Author Shcherbatenko, Michael; Lobanov, Yury; Finkel, Matvey; Maslennikov, Sergey; Pentin, Ivan; Semenov, Alexander; Titova, Nadezhda; Kaurova, Natalya; Voronov, Boris M.; Rodin, Alexander; Klapwijk, Teunis M.; Gol’tsman, Gregory N.
Title Development of a 30 THz heterodyne receiver based on a hot-electron-bolometer mixer Type Abstract
Year 2014 Publication Proc. 25th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 25th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (down) 122
Keywords mid-IR NbN HEB mixers, GaAs substrates
Abstract We present new Hot-Electron-Bolometer (HEB) mixers designed for mid-IR spectroscopy targeting astrophysical and geophysical observations where high sensitivity and spectral resolution are required. The mixers are made of an ultrathin NbN film deposited on GaAs substrates. Two entirely different types of the devices have been fabricated. The first type is based on a direct radiation coupling concept and the mixing devices are shaped as squares of 5×5 μm 2 (which corresponds to the diffraction limit at the chosen wavelength) and 10×10 μm 2 (which was used to establish a possible influence of the contact pads on the radiation absorption). The second type utilizes a spiral antenna designed with HFSS. The fabrication and layout of the devices as well as the performance comparison will be presented. During the experiments, the HEB mixer was installed on the cold plate of a LHe cryostat. A germanium window and an extended semi-spherical germanium lens are used to couple the radiation. The cryostat is equipped with a germanium optical filter of thickness 0.5 mm and with a center wavelength of 10.6 mμ. The incident power absorption is measured by using the isothermal method. As a Local Oscillator, a 10.6 micrometers line of a CO2 gas laser is used. We further characterize the frequency response of the spiral antenna with a FIR-spectrometer. The noise characteristics of the mixers are determined from a room temperature cold load and a heated black body at ~600 K as a hot load.
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Notes Approved no
Call Number Serial 1364
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Author Gousev, Yu. P.; Olsson, H. K.; Gol'tsman, G. N.; Voronov, B. M.; Gershenzon, E. M.
Title NbN hot-electron mixer at radiation frequencies between 0.9 THz and 1.2 THz Type Conference Article
Year 1998 Publication Proc. 9th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 9th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (down) 121-129
Keywords NbN HEB mixers
Abstract We report on noise temperature measurements for a NbN phonon-cooled hot-electron mixer at radiation frequencies between 0.9 THz and 1.2 THz. Radiation was coupled to the mixer, placed in a vacuum chamber of He cryostat, by means of a planar spiral antenna and a Si immersion lens. A backward-wave oscillator, tunable throughout the spectral range, delivered an output power of few 1.1W that was enough for optimum operation of the mixer. At 4.2 K ambient temperature and 1.025 THz radiation frequency, we obtained a receiver noise temperature of 1550 K despite of using a relatively noisy room-temperature amplifier at the intermediate frequency port. The noise temperature was fairly constant throughout the entire operation range and for intermediate frequencies from 1 GHz to 2 GHz.
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Notes Approved no
Call Number Serial 1588
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