News tagged with microwave radiation
Detection of cosmic effect may bring universe's formation into sharper focus
(PhysOrg.com) -- The first observation of a cosmic effect theorized 40 years ago could provide astronomers with a more precise tool for understanding the forces behind the universe's formation and growth, ...
Mar 20, 2012 |
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Researchers find world's first x-ray laser produces most coherent x-ray radiation ever
(PhysOrg.com) -- The world's first x-ray laser, the Linac Coherent Light Source (LCLS), first unveiled in 2009 at the Stanford Linear Accelerator Center in Palo Alto California, has been undergoing testing ...
Oct 03, 2011 |
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Physicists Demonstrate Quantum Memory with Matter Qubits
(PhysOrg.com) -- For the first time, scientists have successfully operated a quantum gate between two remote particles of matter, marking an important step toward the development of a quantum computer. In ...
Jul 03, 2009 |
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New approach to invisibility cloaking gets much closer to the science-fiction version
The idea of being able to become invisible, especially by simply covering up a person or an object with a special cloak, has a perennial appeal in science-fiction and fantasy literature. In recent years, researchers ...
Jan 25, 2011 |
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New Research Promises Better Atomic Clocks
(PhysOrg.com) -- The most accurate timekeepers in the world are atomic clocks, which tell time based on the absorption of a very specific and unchanging microwave frequency, which induces electrons in an atom to “jump” from ...
Apr 22, 2009 |
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Mechanical micro-drum cooled to quantum ground state
Showcasing new tools for widespread development of quantum circuits made of mechanical parts, scientists from the National Institute of Standards and Technology have demonstrated a flexible, broadly usable ...
Jul 06, 2011 |
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Scientist make a leap in quantum computing
(PhysOrg.com) -- A major hurdle in the ambitious quest to design and construct a radically new kind of quantum computer has been finding a way to manipulate the single electrons that very likely will constitute ...
Feb 05, 2010 |
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Ripples in the cosmic background
(PhysOrg.com) -- The universe was created 13.73 billion years ago in a blaze of light -- the big bang. We also think that, about 380,000 years later, after matter (mostly hydrogen atoms) had cooled enough ...
Sep 07, 2010 |
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Researchers propose new way to reproduce a black hole
(PhysOrg.com) -- Despite their popularity in the science fiction genre, there is much to be learned about black holes, the mysterious regions in space once thought to be absent of light. In a paper published in the August ...
Aug 21, 2009 |
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Probing the dark side of the universe
Advancing into the next frontier in astrophysics and cosmology depends on our ability to detect the presence of a particular type of wave in space, a primordial gravitational wave. Much like ripples moving ...
May 20, 2010 |
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Planck satellite unveils the Universe -- now and then (w/ Video)
(PhysOrg.com) -- ESA's Planck mission has delivered its first all-sky image. It not only provides new insight into the way stars and galaxies form but also tells us how the Universe itself came to life after ...
Jul 05, 2010 |
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The earth is not at rest
(Phys.org) -- The Earth is not at rest. It orbits the Sun, which in turn orbits the center of the Milky Way Galaxy, which in turn moves within the Local Group of Galaxies - a collection of about fifty four ...
Apr 18, 2012 |
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Planck first light yields promising results (w/ Video)
(PhysOrg.com) -- Planck, ESA's mission to study the early Universe, started surveying the sky regularly from its vantage point at L2 on 13 August. The instruments of ESA's 'time machine' were fine-tuned for ...
Space & Earth / Space Exploration
Sep 17, 2009 |
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Experts say cellphones are 'possibly carcinogenic'
(AP) -- A respected international panel of scientists says cellphones are possible cancer-causing agents, putting them in the same category as the pesticide DDT, gasoline engine exhaust and coffee.
May 31, 2011 |
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QUIET team to deploy new gravity-wave probe in June
A tiny fraction of a second following the big bang, the universe allegedly experienced the most inflationary period it has ever known.
May 15, 2009 |
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Microwave
Microwaves are electromagnetic waves with wavelengths ranging from 1 m down to 1 mm, or equivalently, with frequencies between 0.3 GHz and 300 GHz.
Apparatus and techniques may be described qualitatively as "microwave" when the wavelengths of signals are roughly the same as the dimensions of the equipment, so that lumped-element circuit theory is inaccurate. As a consequence, practical microwave technique tends to move away from the discrete resistors, capacitors, and inductors used with lower frequency radio waves. Instead, distributed circuit elements and transmission-line theory are more useful methods for design and analysis. Open-wire and coaxial transmission lines give way to waveguides, and lumped-element tuned circuits are replaced by cavity resonators or resonant lines. Effects of reflection, polarization, scattering, diffraction and atmospheric absorption usually associated with visible light are of practical significance in the study of microwave propagation. The same equations of electromagnetic theory apply at all frequencies.
While the name may suggest a micrometer wavelength, it is better understood as indicating wavelengths very much smaller than those used in radio broadcasting. The boundaries between far infrared light, terahertz radiation, microwaves, and ultra-high-frequency radio waves are fairly arbitrary and are used variously between different fields of study. The term microwave generally refers to "alternating current signals with frequencies between 0.3 GHz (3×108 Hz) and 300 GHz (3×1011 Hz)." Both IEC standard 60050 and IEEE standard 100 define "microwave" frequencies starting at 1 GHz (30 cm wavelength).
Electromagnetic waves longer (lower frequency) than microwaves are called "radio waves". Electromagnetic radiation with shorter wavelengths may be called "millimeter waves", terahertz radiation or even T-rays. Definitions differ for millimeter wave band, which the IEEE defines as 110 GHz to 300 GHz.
For more information about Microwave, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
