|
Kawamura J, Blundell R, Tong C-YE, Papa DC, Hunter TR, Paine St. N, et al. Superconductive hot-electron bolometer mixer receiver for 800 GHz operation. Vol 48.; 2000.
|
Meledin DV, Marrone DP, Tong C-YE, Gibson H, Blundell R, Paine SN, et al. A 1-THz superconducting hot-electron-bolometer receiver for astronomical observations. IEEE Trans Microwave Theory Techn. 2004;52(10):2338–43.
Abstract: In this paper, we describe a superconducting hot-electron-bolometer mixer receiver developed to operate in atmospheric windows between 800-1300 GHz. The receiver uses a waveguide mixer element made of 3-4-nm-thick NbN film deposited over crystalline quartz. This mixer yields double-sideband receiver noise temperatures of 1000 K at around 1.0 THz, and 1600 K at 1.26 THz, at an IF of 3.0 GHz. The receiver was successfully tested in the laboratory using a gas cell as a spectral line test source. It is now in use on the Smithsonian Astrophysical Observatory terahertz test telescope in northern Chile.
|
Kawamura J, Blundell R, Tong C‐yu E, Gol’tsman G, Gershenzon E, Voronov B. Performance of NbN lattice‐cooled hot‐electron bolometric mixers. J Appl Phys. 1996;80(7):4232–4.
Abstract: The heterodyne performance of lattice‐cooled hot‐electron bolometric mixers is measured at 200 GHz. Superconducting thin‐film niobium nitride strips with ∼5 nm thickness are used as waveguide mixer elements. A double‐sideband receiver noise temperature of 750 K at 244 GHz is measured at an intermediate frequency centered at 1.5 GHz with 500 MHz bandwidth and with 4.2 K device temperature. The instantaneous bandwidth for this mixer is 1.6 GHz. The local oscillator power required by the mixer is about 0.5 μW. The mixer is linear to within 1 dB up to an input power level 6 dB below the local oscillator power. A receiver incorporating a hot‐electron bolometric mixer was used to detect molecular line emission in a laboratory gascell. This experiment unambiguously confirms that the receiver noise temperature determined from Y‐factor measurements reflects the true heterodyne sensitivity.
|
Tong C-YE, Kawamura J, Todd RH, Papa DC, Blundell R, Smith M, et al. Successful operation of a 1 THz NbN hot-electron bolometer receiver. In: Proc. 11th Int. Symp. Space Terahertz Technol.; 2000. p. 49–59.
Abstract: A phonon-cooled NbN superconductive hot-electron bolometer receiver covering the frequency range 0.8-1.04 THz has successfully been used for astronomical observation at the Sub-Millimeter Telescope Observatory on Mount Graham, Arizona. This waveguide heterodyne receiver is a modified version of our fixed-tuned 800 GHz HEB receiver to allow for operation beyond 1 THz. The measured noise temperature of this receiver is about 1250 K at 0.81 THz, 560 K at 0.84 THz, and 1600 K at 1.035 THz. It has a 1 GHz wide IF bandwidth, centered at 1.8 GHz. This receiver has recently been used to detect the CO (9-8) molecular line emission at 1.037 THz in the Orion nebula. This is the first time a ground-based heterodyne receiver has been used to detect a celestial source above 1 THz.
|
Meledin D, Tong CY-E, Blundell R, Kaurova N, Smirnov K, Voronov B, et al. The sensitivity and IF bandwidth of waveguide NbN hot electron bolometer mixers on MgO buffer layers over crystalline quartz. In: Harvard university, editor. Proc. 13th Int. Symp. Space Terahertz Technol. Cambridge, MA, USA; 2002. p. 65–72.
Abstract: We have developed and characterized waveguide phonon-cooled NbN Hot Electron Bolometer (FMB) mixers fabricated from a 3-4 nm thick NbN film deposited on a 200nm thick MgO buffer layer over crystalline quartz. Double side band receiver noise temperatures of 900-1050 K at 1.035 THz, and 1300-1400 K at 1.26 THz have been measured at an intermediate frequency of 1.5 GHz. The intermediate frequency bandwidth, measured at 0.8 THz LO frequency, is 3.2 GHz at the optimal bias point for low noise receiver operation.
|
