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Search Publications by: Dazhen Gu (Fed)

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Displaying 126 - 142 of 142

STANDARDS DEVELOPMENT FOR REMOTE SENSING AT MICROWAVE AND TERAHERTZ FREQUENCIES

September 7, 2007
Author(s)
James P. Randa, Eyal Gerecht, Dave K. Walker, Amanda Cox, Dazhen Gu, Lixing You, Robert L. Billinger
The Noise Project in the Electromagnetics Division of the National Institute of Standards and Technology (NIST) has proposed the development of standards for microwave brightness temperature, for use in remote-sensing applications such as satellite-based

Terahertz radiometer design for traceable noise-temperature measurements

July 14, 2006
Author(s)
Eyal Gerecht, Dazhen Gu, James P. Randa, Dave K. Walker, Robert L. Billinger
We report on design of a radiometer for traceable noise-temperature measurements at terahertz frequencies, including noise measurements on cryogenic IF components, development and test of quasi-optical adapter technology, development of black body

A Two-Dimensional Terahertz Imaging System Using Hot Electron Bolometer

May 10, 2006
Author(s)
Dazhen Gu, Eyal Gerecht, Fernando Rodriquez Morales, Sigfrid Yngvesson
We present first results with a two-dimensional(2D)scanning, terahertz passive heterodyne imaging system currently under development. The imager is based on a phonon-cooled quasi-optically coupled HEB mixer integrated with an InP MMIC IF low-noise

Precision Measurement Method for Cryogenic Amplifier Noise Temperatures Below 5 K

March 1, 2006
Author(s)
James P. Randa, Eyal Gerecht, Dazhen Gu, Robert L. Billinger
We report precision measurements of the effective input noise temperature of a cryogenic (liquid helium temperature) MMIC amplifier at the amplifier reference planes within the cryostat. A method is given for characterizing and removing the effect of the

HEB FPA Imaging Technology for Security and Biomedical Applications

September 19, 2005
Author(s)
Eyal Gerecht, Dazhen Gu, Sigfrid Yngvesson, Fernando Rodriguez-Morales, Ric Zannoni, John Nicholson
We have demonstrated a low-noise heterodyne three-element focal plane array (FPA) at 1.6 THz consisting of NbN Hot Electron Bolometric (HEB) detectors, intimately integrated with MMIC IF amplifiers in a single block. HEB technology is becoming the basis