Download or read book Noise Temperature Measurement System For The WR 28 Band NIST Technical Note 1395 U S Department Of Commerce written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Noise temperature Measurement System for the WR 28 Band written by and published by . This book was released on 1997 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NIST Noise Project has constructed and tested a radiometer for the measurement of noise sources in the WR-28 waveguide band (26.5 GHz to 40 GHz). it is a total-power radiometer which incorporates a six-port reflectometer for the measurement of relevant reflection coefficients. The radiometer is similar in design to existing NIST systems covering the WR-62 (12.4 GHz to 18 GHz) and WR-42 (18 GHz to 26.5 GHz) bands. This paper reviews the theory and describes the design, testing, and operation of the system. Because of the similarities between the present system and the existing WR-62 and WR-42 systems, much of this document also applies to those systems.
Download or read book Noise Temperature Measurement System for the Wr 28 Band Classic Reprint written by James Randa and published by Forgotten Books. This book was released on 2017-12-14 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Noise-Temperature Measurement System for the Wr-28 Band Before proceeding, we establish some notation and conventions. We use the term noise temperature to mean the spectral density of available power from the source, divided by Boltzmann's constant. Thus for a small bandwidth B, over which the available power density is constant, the available power is given by P kbbtn. Available powers will be denoted by capital P, and delivered powers by lowercase p. The subscript on an available power generally indicates the device, except in the case of P where it indicates the ambient. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
Download or read book NISTIR written by and published by . This book was released on 2001 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design and Testing of NFRad written by Chriss A. Grosvenor and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book UNCERTAINTIES IN NIST NOISE TEMPERATURE MEASUREMENTS NIST TECHNICAL 1502 U S DEPARTMENT OF COMMERCE written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1998* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Noise Temperature Measurements on Wafer written by J. Randa and published by . This book was released on 1997 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NIST Noise Project has developed the theoretical formalism and experimental methods for performing accurate noise-temperature measurements on wafer. This report presents the theoretical formulation and describes the design, methods, and results of tests performed to verify our ability to measure on-wafer noise temperature. With known off-wafer noise sources, several different configurations were used to obtain different, known, on-wafer noise temperatures. These were then measured, and the results were compared to predictions. Good agreement was found, with a worst-case disagreement of 2.6 percent. An uncertainty analysis of the measurements resulted in an estimated standard uncertainty (1o) of 1.1. percent or less for most vlues of noise temperature. The tests also confirm our ability to produce known noise temperatures on wafer.
Download or read book The NIST 30 60 MHz Tuned Radiometer for Noise Temperature Measurements written by Chriss A. Grosvenor and published by . This book was released on 2002 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NIST Noise Project has completed reconstruction of their 30/60 MHz tuned, coaxial (Type N) radiometer system. This system is used at low frequencies where isolators are impractical to incorporate. Without isolators, the ambient and cryogenic standards are tuned to the impedance fo the device under test to minimize mismatches. Although this system had been in existence prior to this technical note, enough modifications and improvements have been made to warrant a new discussion. This note will briefly review the original system, discuss the theory as well as the design, testing, and capabiaities of the present system. A more detailed uncertainty analysis is included and an appendix for troubleshooting the system.
Download or read book WR 10 Band Noise Measurement written by and published by . This book was released on 1992 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: A WR-10 band (75 to 110 GHz) noise measurement system was developed to evaluate a solid state noise source in this band. The system was characterized with a gas discharge tube that provided a stable output Excess Noise Ratio (ENR) of 14.2 dB + 0.5 dB throughout the band. To ensure the accuracy of the system characterization, the results were correlated with the results of noise temperature measurements, obtained from a load maintained at ambient and liquid nitrogen temperatures. The principles of noise measurement, method and limitations of each technique, and results of receiver characterization are discussed. The results of the receiver characterization are applied to the evaluation of solid-state noise sources. The resulting double sideband (DSB) ENR of the noise sources are presented and discussed. The accuracy of this DSB evaluation was compared to a single sideband (SSB) measurement using the "Three Point Measurement" method. Two WR-10 band noise sources were evaluated with the noise measurement system developed at NRL. The device performance was specified as an ENR of 15 dB + 1 dB and full waveguide coverage. The actual performance results indicate that ENR values in excess of 15 dB are available, but the devices lacked a flat output over the band.
Download or read book Time and Frequency Theory and Fundamentals written by Byron Emerson Blair and published by . This book was released on 1974 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: The document is a tutorial Monograph describing various aspects of time and frequency (T/F). Included are chapters relating to elemental concepts of precise time and frequency; basic principles of quartz oscillators and atomic frequency standards; historical review, recent progress, and current status of atomic frequency standards; promising areas for developing future primary frequency standards; relevance of frequency standards to other areas of metrology including a unified standard concept; statistics of T/F data analysis coupled with the theory and construction of the NBS atomic time scale; an overview of T/F dissemination techniques; and the standards of T/F in the USA. The Monograph addresses both the specialist in the field as well as those desiring basic information about time and frequency. The authors trace the development and scope of T/F technology, its improvement over periods of decades, its status today, and its possible use, applications, and development in days to come.
Download or read book Index of International Standards written by Sophie J. Chumas and published by . This book was released on 1974 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Induced Damage in Optical Materials 1976 written by Alexander J. Glass and published by . This book was released on 1976 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Responsible Conduct of Research written by Adil E. Shamoo and published by Oxford University Press. This book was released on 2009-02-12 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent scandals and controversies, such as data fabrication in federally funded science, data manipulation and distortion in private industry, and human embryonic stem cell research, illustrate the importance of ethics in science. Responsible Conduct of Research, now in a completely updated second edition, provides an introduction to the social, ethical, and legal issues facing scientists today.
Download or read book Converging Technologies for Improving Human Performance written by William Sims Bainbridge and published by Springer. This book was released on 2014-03-14 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: M. C. Roco and W.S. Bainbridge In the early decades of the 21st century, concentrated efforts can unify science based on the unity of nature, thereby advancing the combination of nanotechnology, biotechnology, information technology, and new technologies based in cognitive science. With proper attention to ethical issues and societal needs, converging in human abilities, societal technologies could achieve a tremendous improvement outcomes, the nation's productivity, and the quality of life. This is a broad, cross cutting, emerging and timely opportunity of interest to individuals, society and humanity in the long term. The phrase "convergent technologies" refers to the synergistic combination of four major "NBIC" (nano-bio-info-cogno) provinces of science and technology, each of which is currently progressing at a rapid rate: (a) nanoscience and nanotechnology; (b) biotechnology and biomedicine, including genetic engineering; (c) information technology, including advanced computing and communications; (d) cognitive science, including cognitive neuroscience. Timely and Broad Opportunity. Convergence of diverse technologies is based on material unity at the nanoscale and on technology integration from that scale.
Download or read book Nanotechnology Research Directions IWGN Workshop Report written by R.S. Williams and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: energy production, environmental management, transportation, communication, computation, and education. As the twenty-first century unfolds, nanotechnology's impact on the health, wealth, and security of the world's people is expected to be at least as significant as the combined influences in this century of antibiotics, the integrated circuit, and human-made polymers. Dr. Neal Lane, Advisor to the President for Science and Technology and former National Science Foundation (NSF) director, stated at a Congressional hearing in April 1998, "If I were asked for an area of science and engineering that will most likely produce the breakthroughs of tomorrow, I would point to nanoscale science and engineering. " Recognizing this potential, the White House Office of Science and Technology Policy (OSTP) and the Office of Management and Budget (OMB) have issued a joint memorandum to Federal agency heads that identifies nanotechnology as a research priority area for Federal investment in fiscal year 2001. This report charts "Nanotechnology Research Directions," as developed by the Interagency W orking Group on Nano Science, Engineering, and Technology (IWGN) of the National Science and Technology Council (NSTC). The report incorporates the views of leading experts from government, academia, and the private sector. It reflects the consensus reached at an IWGN-sponsored workshop held on January 27-29, 1999, and detailed in contributions submitted thereafter by members of the V. S. science and engineering community. (See Appendix A for a list of contributors.
Download or read book Femtosecond Optical Frequency Comb Principle Operation and Applications written by Jun Ye and published by Springer Science & Business Media. This book was released on 2006-06-15 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last few years, there has been a convergence between the fields of ultrafast science, nonlinear optics, optical frequency metrology, and precision laser spectroscopy. These fields have been developing largely independently since the birth of the laser, reaching remarkable levels of performance. On the ultrafast frontier, pulses of only a few cycles long have been produced, while in optical spectroscopy, the precision and resolution have reached one part in Although these two achievements appear to be completely disconnected, advances in nonlinear optics provided the essential link between them. The resulting convergence has enabled unprecedented advances in the control of the electric field of the pulses produced by femtosecond mode-locked lasers. The corresponding spectrum consists of a comb of sharp spectral lines with well-defined frequencies. These new techniques and capabilities are generally known as “femtosecond comb technology. ” They have had dramatic impact on the diverse fields of precision measurement and extreme nonlinear optical physics. The historical background for these developments is provided in the Foreword by two of the pioneers of laser spectroscopy, John Hall and Theodor Hänsch. Indeed the developments described in this book were foreshadowed by Hänsch’s early work in the 1970s when he used picosecond pulses to demonstrate the connection between the time and frequency domains in laser spectroscopy. This work complemented the advances in precision laser stabilization developed by Hall.
Download or read book Climate Intervention written by National Research Council and published by National Academies Press. This book was released on 2015-06-23 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growing problem of changing environmental conditions caused by climate destabilization is well recognized as one of the defining issues of our time. The root problem is greenhouse gas emissions, and the fundamental solution is curbing those emissions. Climate geoengineering has often been considered to be a "last-ditch" response to climate change, to be used only if climate change damage should produce extreme hardship. Although the likelihood of eventually needing to resort to these efforts grows with every year of inaction on emissions control, there is a lack of information on these ways of potentially intervening in the climate system. As one of a two-book report, this volume of Climate Intervention discusses albedo modification - changing the fraction of incoming solar radiation that reaches the surface. This approach would deliberately modify the energy budget of Earth to produce a cooling designed to compensate for some of the effects of warming associated with greenhouse gas increases. The prospect of large-scale albedo modification raises political and governance issues at national and global levels, as well as ethical concerns. Climate Intervention: Reflecting Sunlight to Cool Earth discusses some of the social, political, and legal issues surrounding these proposed techniques. It is far easier to modify Earth's albedo than to determine whether it should be done or what the consequences might be of such an action. One serious concern is that such an action could be unilaterally undertaken by a small nation or smaller entity for its own benefit without international sanction and regardless of international consequences. Transparency in discussing this subject is critical. In the spirit of that transparency, Climate Intervention: Reflecting Sunlight to Cool Earth was based on peer-reviewed literature and the judgments of the authoring committee; no new research was done as part of this study and all data and information used are from entirely open sources. By helping to bring light to this topic area, this book will help leaders to be far more knowledgeable about the consequences of albedo modification approaches before they face a decision whether or not to use them.
