منابع مشابه
National Radio Astronomy Observatory
As part of an initiative to reduce the size, weight, and complexity of radio astronomy receivers and to place the conversion from analog to digital signals as close to the telescope feed as possible, a prototype single-conversion, sideband-separating mixer receiver with a tunable local oscillator (LO) between 5 and 9 GHz has been built and tested. After straightforward gain and phase calibratio...
متن کاملNational Radio Astronomy Observatory
Measurements of microwave attenuation at room temperature and 4.2 K have been performed on some conductors commonly used in receiver input circuits. The reduction in loss on cooling is substantial, particularly for copper and plated gold, both of which showed a factor of 3 loss reduction. Copper passivated with benzotriazole shows the same loss as without passivation. The residual resistivity r...
متن کاملNational Radio Astronomy Observatory
The existing waveguide interface standards are generally found to be unsatisfactory above 110 GHz. An improved interface is proposed which is backward-compatible with the MIL-DTL-3922/67C standard and most of its higher-frequency variants. As there are currently no standard waveguide bands above 325 GHz, an extended set of bands is recommended for operation to 1100 GHz. Index Terms — Waveguides...
متن کاملNFRA’s Radio Observatory: Policies and Procedures
Since the end of 1999 there has been a brand new WSRT standing in the community of Hooghalen, The Netherlands. Although the Upgrade of the Westerbork Synthesis Radio Telescope is not totally completed, major parts of all the envisioned state-of-the-art systems have been installed and are operating. This Newsletter is designed to let the national and international astronomy community know about ...
متن کاملAn Anomalous Peak on Intermediate Frequency Response of Superconductor-Isolator-Superconductor Mixers and Its Effect on Mixing Performance
of Superconductor-Isolator-Superconductor Mixers and Its Effect on Mixing Performance Wenlei SHAN, Mingjye WANG, Shengcai SHI, Yoshihisa IRIMAJIRI and Takeshi NOGUCHI Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Nobeyama, Nagano 384-1305, Japan Purple Mountain Observatory, National Astronomical Observatories of China, Nanjing 210008, China Institute of Astronomy and A...
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ژورنال
عنوان ژورنال: Biological Sciences in Space
سال: 1987
ISSN: 0914-9201,1349-967X
DOI: 10.2187/bss.1.39