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Pütz P., Büchel D., Jacobs K., Schultz M., Honingh C.E., & Stutzki J. (2014). Waveguide Hot Electron Bolometer Mixer development for upGREAT. Kosma, .
Abstract: We report on our hot electron bolometer mixer development for the focal plane array extension upGREAT of the German Receiver for Astronomy at Terahertz frequencies (GREAT) operated on SOFIA. For (up)GREAT we have pushed the waveguide technology to 4.7 THz and present RF performance results. We describe the RF planar circuit design, the micro fabrication employing NbN microbridges on 2 µm thin Si membrane substrates and the machining technology used for the waveguides. One of the 4.7 THz mixers was used in the high frequency channel on GREAT in May 2014 and performed as expected from the laboratory characterization.
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Floet D. W., Gao J. R., Klapwijk T. M., & de Korte P. A. J. (2000). Bias Dependence of the Thermal Time Constant in Nb Superconducting Diffusion-Cooled HEB Mixers. Appl. Phys. Lett., 77, 1719.
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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Meledin D., Pantaleev M., Pavolotsky A., Risacher C., Robles V.A.P., Belitsky V., et al. (2004). Design of a balanced waveguide HEB mixer for APEX 1.32 THz receiver. In Proc. 15th Int. Symp. Space Terahertz Technol. (pp. 211–217).
Abstract: The prototype of a waveguide balanced Hot Electron Bolometer (HEB) Terahertz mixer is designed as a part of development for the APEX Project of Band T2 receiver for 1250-1390 GHz. The proposed mixer employs balanced scheme with two identical HEB devices. These individual mixers would be placed on two separate crystalline quartz substrates with dimensions of 1000μm x67μm x17 μm each with integrated RF choke filters, DC-bias and IF circuitry. A 3 dB quadrature waveguide directional coupler is needed to provide local oscillator (LO) injection and RF signal distribution between the two HEB mixers. We have designed the coupler to achieve the required frequency band, low insertion loss and symmetrical division of the RF and LO power within the band of interest. Initial design of HEB mixer layout is developed based on a previous development for a 345 GHz sideband separation mixer. We present also results of development of microfabrication technology of the waveguide hybrid employing micromachining approach combined with electroplating technique.
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Корнеева, Ю. П., Флоря, И. Н., Корнеев, А. А., & Гольцман, Г. Н. (2010). Cверхпроводящий однофотонный детектор для дальнего ИК диапазона длин волн. In Науч. сессия НИЯУ МИФИ (pp. 46–47).
Abstract: Мы представляем быстродействующий сверхпроводниковый однофотонный детектор (SSPD) для дальнего инфракрасного диапазона на основе ультратонкой монокристаллической пленки NbN толщиной 3 нм, состоящий из параллельных полосок. QE на длине волны 1,5.μм и 1,3 μм для предложенного SSPD практически одинаковы. SSPD показывает отклик длительностью 200 пс, что открывает путь к детекторам, обладающим скоростью счета свыше 1 ГГц.
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Meledin D., Desmaris V., Ferm S.-E., Fredrixon M., Henke D., Lapkin I., et al. (2008). APEX Band T2: A 1.25 – 1.39 THz Waveguide Balanced HEB Receiver.181–185.
Abstract: A waveguide 1.25–1.39 THz Hot Electron Bolometer (HEB) balanced receiver was successfully developed, characterized and installed at the Atacama Pathfinder EXperiment (APEX) telescope. The receiver employs a quadrature balanced scheme using a waveguide 90-degree 3 dB RF hybrid, HEB mixers and a 180-degree IF hybrid. The HEB mixers are based on ultrathin NbN film deposited on crystalline quartz with a MgO buffer layer. Integrated into the multi-channel APEX facility receiver (SHeFI), the results presented here demonstrate exceptional performance; a receiver noise temperature of 1000 K measured at the telescope at the center of the receiver IF band 2-4 GHz, and at an LO frequency of 1294 GHz. Stability of the receiver is fully in line with the SIS mixer bands of the SHeFI, and gives a spectroscopic Allan time of more than 200 s with a noise bandwidth of 1 MHz.
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