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| Author | Lobanov, Y.V.; Tong, C.-Y.E.; Hedden, A.S.; Blundell, R.; Voronov, B.M.; Gol'tsman, G.N. | ||||
| Title | Direct measurement of the gain and noise bandwidths of HEB mixers | Type  |
Journal Article | ||
| Year | 2011 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
| Volume | 21 | Issue | 3 | Pages | 645-648 |
| Keywords | waveguide NbN HEB mixers | ||||
| Abstract | The intermediate frequency (IF) bandwidth of a hot electron bolometer (HEB) mixer is an important parameter of the mixer, in that it helps to determine its suitability for a given application. With the availability of wideband low noise amplifiers, it is simple to measure the performance of an HEB mixer over a wide range of IF at a fixed LO frequency using the standard Y-factor method. This in-situ method allows us to measure both the gain and noise bandwidths simultaneously. We have also measured mixer output impedance with a vector network analyser. Intrinsic time constant has been extracted from the impedance data and compared to the mixer's bandwidths determined from receiver Y-factor measurement. | ||||
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| Notes | Approved | no | |||
| Call Number | RPLAB @ gujma @ | Serial | 720 | ||
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| Author | Burke, P. J.; Schoelkopf, R. J.; Prober, D. E.; Skalare, A.; Karasik, B. S.; Gaidis, M. C.; McGrath, W. R.; Bumble, B.; Leduc, H. G. | ||||
| Title | Spectrum of thermal fluctuation noise in diffusion and phonon cooled hot-electron mixers | Type |
Journal Article | ||
| Year | 1998 | Publication | Applied Physics Letters | Abbreviated Journal | Appl. Phys. Lett. |
| Volume | 72 | Issue | 12 | Pages | 1516-1518 |
| Keywords | HEB mixer; thermal fluctuation noise; TFN | ||||
| Abstract | A systematic study of the intermediate frequency noise bandwidth of Nb thin-film superconducting hot-electron bolometers is presented. We have measured the spectrum of the output noise as well as the conversion efficiency over a very broad intermediate frequency range (from 0.1 to 7.5 GHz) for devices varying in length from 0.08 μm to 3 μm. Local oscillator and rf signals from 8 to 40 GHz were used. For a device of a given length, the spectrum of the output noise and the conversion efficiency behave similarly for intermediate frequencies less than the gain bandwidth, in accordance with a simple thermal model for both the mixing and thermal fluctuation noise. For higher intermediate frequencies the conversion efficiency decreases; in contrast, the noise decreases but has a second contribution which dominates at higher frequency. The noise bandwidth is larger than the gain bandwidth, and the mixer noise is low, between 120 and 530 K (double side band). | ||||
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| Notes | Approved | no | |||
| Call Number | RPLAB @ gujma @ | Serial | 760 | ||
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| Author | Pütz, P.; Honingh, C. E.; Jacobs, K.; Justen, M.; Schultz, M.; Stutzki, J. | ||||
| Title | Terahertz hot electron bolometer waveguide mixers for GREAT | Type |
Journal Article | ||
| Year | 2012 | Publication | Astron. Astrophys. | Abbreviated Journal | A&A |
| Volume | 542 | Issue | Pages | L2 | |
| Keywords | HEB mixer, applications | ||||
| Abstract | Context. Supplementing the publications based on the first-light observations with the German REceiver for Astronomy at Terahertz frequencies (GREAT) on SOFIA, we present background information on the underlying heterodyne detector technology. This Letter complements the GREAT instrument Letter and focuses on the mixers itself. Aims. We describe the superconducting hot electron bolometer (HEB) detectors that are used as frequency mixers in the L1 (1400 GHz), L2 (1900 GHz), and M (2500 GHz) channels of GREAT. Measured performance of the detectors is presented and background information on their operation in GREAT is given. Methods. Our mixer units are waveguide-based and couple to free-space radiation via a feedhorn antenna. The HEB mixers are designed, fabricated, characterized, and flight-qualified in-house. We are able to use the full intermediate frequency bandwidth of the mixers using silicon-germanium multi-octave cryogenic low-noise amplifiers with very low input return loss. Results. Superconducting HEB mixers have proven to be practical and sensitive detectors for high-resolution THz frequency spectroscopy on SOFIA. We show that our niobium-titanium-nitride (NbTiN) material HEBs on silicon nitride (SiN) membrane substrates have an intermediate frequency (IF) noise roll-off frequency above 2.8 GHz, which does not limit the current receiver IF bandwidth. Our mixer technology development efforts culminate in the first successful operation of a waveguide-based HEB mixer at 2.5 THz and deployment for radioastronomy. A significant contribution to the success of GREAT is made by technological development, thorough characterization and performance optimization of the mixer and its IF interface for receiver operation on SOFIA. In particular, the development of an optimized mixer IF interface contributes to the low passband ripple and excellent stability, which GREAT demonstrated during its initial successful astronomical observation runs. |
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| Notes | Approved | no | |||
| Call Number | Serial | 907 | |||
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| Author | Cherednichenko, Sergey; Drakinskiy, Vladimir; Berg, Therese; Khosropanah, Pourya; Kollberg, Erik | ||||
| Title | Hot-electron bolometer terahertz mixers for the Herschel Space Observatory | Type |
Journal Article | ||
| Year | 2008 | Publication | Review of Scientific Instruments | Abbreviated Journal | Rev. Sci. Instrum. |
| Volume | 79 | Issue | Pages | 034501 | |
| Keywords | HEB mixer, HEB detector, HEB direct detector, applications | ||||
| Abstract | We report on low noise terahertz mixers(1.4–1.9THz) developed for the heterodyne spectrometer onboard the Herschel Space Observatory. The mixers employ double slot antenna integrated superconducting hot-electron bolometers (HEBs) made of thin NbN films. The mixer performance was characterized in terms of detection sensitivity across the entire rf band by using a Fourier transform spectrometer (from 0.5to2.5THz, with 30GHz resolution) and also by measuring the mixernoise temperature at a limited number of discrete frequencies. The lowest mixernoise temperature recorded was 750K [double sideband (DSB)] at 1.6THz and 950KDSB at 1.9THz local oscillator (LO) frequencies. Averaged across the intermediate frequency band of 2.4–4.8GHz, the mixernoise temperature was 1100KDSB at 1.6THz and 1450KDSB at 1.9THz LO frequencies. The HEB heterodyne receiver stability has been analyzed and compared to the HEB stability in the direct detection mode. The optimal local oscillator power was determined and found to be in a 200–500nW range. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 908 | |||
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| Author | Yagoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Gol'tsman, G.; Svechnikov, S.; Gershenzon, E. | ||||
| Title | Noise temperature and local oscillator power requirement of NbN phonon-cooled hot electron bolometric mixers at terahertz frequencies | Type |
Journal Article | ||
| Year | 1998 | Publication | Appl. Phys. Lett. | Abbreviated Journal | Appl. Phys. Lett. |
| Volume | 73 | Issue | 19 | Pages | 2814-2816 |
| Keywords | NbN HEB mixers, noise temperature, local oscillator power | ||||
| Abstract | In this letter, the noise performance of NbN-based phonon-cooled hot electron bolometric quasioptical mixers is investigated in the 0.55–1.1 THz frequency range. The best results of the double-sideband <cd><2018>DSB<cd><2019> 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 significant contribution to the measured receiver noise temperature around 1.1 THz. The devices are made from 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 typically 0.2Ï«2 um. The amount of local oscillator power absorbed in the bolometer is less than 100 nW. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 911 | |||
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