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Cherednichenko, S., Drakinskiy, V., Berg, T., Kollberg, E. L., & Angelov, I. (2007). The direct detection effect in the hot-electron bolometer mixer sensitivity calibration. IEEE Trans. Microw. Theory Techn., 55(3), 504–510.
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Ryabchun, S., Tong, C. - Y. E., Blundell, R., & Gol'tsman, G. (2009). Stabilization scheme for hot-electron bolometer receivers using microwave radiation. IEEE Trans. Appl. Supercond., 19(1), 14–19.
Abstract: We present the results of a stabilization scheme for terahertz receivers based on NbN hot-electron bolometer (HEB) mixers that uses microwave radiation with a frequency much lower than the gap frequency of NbN to compensate for mixer current fluctuations. A feedback control loop, which actively controls the power level of the injected microwave radiation, has successfully been implemented to stabilize the operating point of the HEB mixer. This allows us to increase the receiver Allan time to 10 s and also improve the temperature resolution of the receiver by about 30% in the total power mode of operation.
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Kawamura, J., Blundell, R., Tong, C. - Y. E., Papa, D. C., Hunter, T. R., Paine, S. N., et al. (2000). Superconductive hot-electron-bolometer mixer receiver for 800-GHz operation. IEEE Trans. Microw. Theory Techn., 48(4), 683–689.
Abstract: In this paper, we describe a superconductive hot-electron-bolometer mixer receiver designed to operate in the partially transmissive 350-μm atmospheric window. The receiver employs an NbN thin-film microbridge as the mixer element, in which the main cooling mechanism of the hot electrons is through electron-phonon interaction. At a local-oscillator frequency of 808 GHz, the measured double-sideband receiver noise temperature is TRX=970 K, across a 1-GHz intermediate-frequency bandwidth centered at 1.8 GHz. We have measured the linearity of the receiver and the amount of local-oscillator power incident on the mixer for optimal operation, which is PLO≈1 μW. This receiver was used in making observations as a facility instrument at the Heinrich Hertz Telescope, Mt. Graham, AZ, during the 1998-1999 winter observing season.
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Tong, C. - Y. E., Meledin, D. V., Marrone, D. P., Paine, S. N., Gibson, H., & Blundell, R. (2003). Near field vector beam measurements at 1 THz. IEEE Microw. Compon. Lett., 13(6), 235–237.
Abstract: We have performed near-field vector beam measurements at 1.03 THz to characterize and align the receiver optics of a superconducting receiver. The signal source is a harmonic generator mounted on an X-Y translation stage. We model the measured two-dimensional complex beam pattern by a fundamental Gaussian mode, from which we derive the position of the beam center, the beam radius and the direction of propagation. By performing scans in the planes separated by 400 mm, we have confirmed that our beam pattern measurements are highly reliable.
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Cao, A., Jiang, L., Chen, S. H., Antipov, S. V., & Shi, S. C. (2007). IF gain bandwidth of a quasi-optical NbN superconducting HEB mixer. In Proc. International conference on microwave and millimeter wave technology (pp. 1–3). Builin.
Abstract: In this paper, the intermediate frequency (IF) gain bandwidth of a quasi-optical NbN superconducting hot-electron bolometer (HEB) mixer is investigated at 500 GHz with an IF system incorporating with a frequency down-converting scheme which is able to sweep the IF signal in a frequency range of 0.3-4 GHz. The IF gain bandwidth of the device is measured to be 1.5 GHz when it is biased at a voltage of the minimum noise temperature, and becomes larger when the bias voltage increases.
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Gershenzon, E. M., Gershenzon, M. E., Gol'tsman, G. N., Semenov, A. D., & Sergeev, A. V. (1984). Heating of electrons in a superconductor in the resistive state by electromagnetic radiation. Sov. Phys. JETP, 59(2), 442–450.
Abstract: The effect of heating of electrons relative to phonons is observed and investigated in a superconducting film that is made resistive by current and by an external magnetic field. The effect is manifested by an increase of the film resistance under the influence of the electromagnetic radiation, and is not selective in the frequency band 10^10-10^15 Hz. The independence of the effect of frequency under conditions of strong scattering by static defects is attributed to the decisive role of electron-electron collisions in the distribution function. The experimentally obtained characteristic time of resistance variation near the superconducting transition corresponds to the relaxation time of the order parameter, while at lower temperatures and fields it corresponds to the time of the inelastic electron-phonon interaction.
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Hajenius, M., Baselmans, J. J. A., Baryshev, A., Gao, J. R., Klapwijk, T. M., Kooi, J. W., et al. (2006). Full characterization and analysis of a terahertz heterodyne receiver based on a NbN hot electron bolometer. J. Appl. Phys., 100(7), 074507.
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Гольцман, Г. Н., & Лудков, Д. Н. (2003). Сверхпроводниковые смесители на горячих электронах терагерцового диапазона и их применение в радиоастрономии. Изв. высших учебных заведений. Радиофизика, 46(8/9).
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Uzawa, Y., Miki, S., Wang, Z., Kawakami, A., Kroug, M., Yagoubov, P., et al. (2002). Performance of a quasi-optical NbN hot-electron bolometric mixer at terahertz frequencies. Supercond. Sci. Technol., 15(1), 141–145.
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Gershenson, M. E., Gong, D., Sato, T., Karasik, B. S., & Sergeev, A. V. (2001). Millisecond electron-phonon relaxation in ultrathin disordered metal films at millikelvin temperatures. Appl. Phys. Lett., 79, 2049–2051.
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