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Anechoic Chamber
An anechoic chamber (''an-echoic'' meaning "non-reflective" or "without echoes") is a room designed to stop reflection (physics), reflections or Echo (phenomenon), echoes of either sound or electromagnetic waves. They are also often isolated from energy entering from their surroundings. This combination means that a person or detector exclusively hears direct sounds (no reverberation, reflected sounds), in effect simulating being outside in a free field. Anechoic chambers, a term coined by American acoustics expert Leo Beranek, were initially exclusively used to refer to acoustic anechoic chambers. Recently, the term has been extended to other radio frequency (RF) and sonar anechoic chambers, which eliminate reflection and external noise caused by electromagnetic waves. Anechoic chambers range from small compartments the size of household microwave ovens to ones as large as aircraft hangars. The size of the chamber depends on the size of the objects and frequency ranges bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
360 Anechoic Chamber Salford University Uk
36 may refer to: * 36 (number) * 36 BC * AD 36 * 1936 * 2036 Science * Krypton, a noble gas in the periodic table * 36 Atalante, an asteroid in the asteroid belt Arts and entertainment * 36 (TV series), ''36'' (TV series), an American sports documentary show * "36", a 2002 song by System of a Down from ''Steal This Album!'' * 36 Quai des Orfèvres (film), a 2004 French crime film * "Thirty Six", a song by Karma to Burn from the album ''Almost Heathen'', 2001 {{Numberdis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directivity
In electromagnetics, directivity is a parameter of an antenna or optical system which measures the degree to which the radiation emitted is concentrated in a single direction. It is the ratio of the radiation intensity in a given direction from the antenna to the radiation intensity averaged over all directions.IEEE Std 145-2013, IEEE Standard for Definitions of Terms for Antennas, IEEE Therefore, the directivity of a hypothetical isotropic radiator, a source of electromagnetic waves which radiates the same power in all directions, is 1, or 0 dBi. An antenna's directivity is greater than its gain by an efficiency factor, radiation efficiency. Directivity is an important measure because many antennas and optical systems are designed to radiate electromagnetic waves in a single direction or over a narrow-angle. By the principle of reciprocity, the directivity of an antenna when receiving is equal to its directivity when transmitting. The directivity of an actual antenn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellular Network
A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless network, wireless and the network is distributed over land areas called ''cells'', each served by at least one fixed-location transceiver (such as a base station). These base stations provide the cell with the network coverage which can be used for transmission of voice, data, and other types of content via radio waves. Each cell's coverage area is determined by factors such as the power of the transceiver, the terrain, and the frequency band being used. A cell typically uses a different set of frequencies from neighboring cells, to avoid interference and provide guaranteed service quality within each cell. When joined together, these cells provide radio coverage over a wide geographic area. This enables numerous Mobile device, devices, including mobile phones, Tablet computer, tablets, laptops equipped with mobile broadband modems, and Wearable technology, wea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Pattern
In the field of antenna design the term radiation pattern (or antenna pattern or far-field pattern) refers to the ''directional'' (angular) dependence of the strength of the radio waves from the antenna or other source.Constantine A. Balanis: "Antenna Theory, Analysis and Design", John Wiley & Sons, Inc., 2nd ed. 1982 David K Cheng: "Field and Wave Electromagnetics", Addison-Wesley Publishing Company Inc., Edition 2, 1998. Edward C. Jordan & Keith G. Balmain; "Electromagnetic Waves and Radiating Systems" (2nd ed. 1968) Prentice-Hall. Particularly in the fields of fiber optics, lasers, and integrated optics, the term radiation pattern may also be used as a synonym for the near-field pattern or Fresnel pattern.Institute of Electrical and Electronics Engineers, "The IEEE standard dictionary of electrical and electronics terms"; 6th ed. New York, N.Y., Institute of Electrical and Electronics Engineers, c1997. IEEE Std 100-1996. d. Standards Coordinating Committee 10, Terms and D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antenna (radio)
In radio-frequency engineering, an antenna (American English) or aerial (British English) is an electronic device that converts an alternating current, alternating electric current into radio waves (transmitting), or radio waves into an electric current (receiving). It is the interface between radio waves Radio propagation, propagating through space and electric currents moving in metal Electrical conductor, conductors, used with a transmitter or receiver (radio), receiver. In transmission (telecommunications), transmission, a radio transmitter supplies an electric current to the antenna's Terminal (electronics), terminals, and the antenna radiates the energy from the current as electromagnetic radiation, electromagnetic waves (radio waves). In receiver (radio), reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplifier, amplified. Antennas are essential components ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar Absorbent Material
In materials science, radiation-absorbent material (RAM) is a material which has been specially designed and shaped to absorb incident RF radiation (also known as non-ionising radiation), as effectively as possible, from as many incident directions as possible. The more effective the RAM, the lower the resulting level of reflected RF radiation. Many measurements in electromagnetic compatibility (EMC) and antenna radiation patterns require that spurious signals arising from the test setup, including reflections, are negligible to avoid the risk of causing measurement errors and ambiguities. Introduction One of the most effective types of RAM comprises arrays of pyramid-shaped pieces, each of which is constructed from a suitably lossy material. To work effectively, all internal surfaces of the anechoic chamber must be entirely covered with RAM. Sections of RAM may be temporarily removed to install equipment but they must be replaced before performing any tests. To be suffic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
40th Flight Test Squadron F-16 Fighting Falcon Sits In The Anechoic Chamber
4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is a square number, the smallest semiprime and composite number, and is considered unlucky in many East Asian cultures. Evolution of the Hindu-Arabic digit Brahmic numerals represented 1, 2, and 3 with as many lines. 4 was simplified by joining its four lines into a cross that looks like the modern plus sign. The Shunga would add a horizontal line on top of the digit, and the Kshatrapa and Pallava evolved the digit to a point where the speed of writing was a secondary concern. The Arabs' 4 still had the early concept of the cross, but for the sake of efficiency, was made in one stroke by connecting the "western" end to the "northern" end; the "eastern" end was finished off with a curve. The Europeans dropped the finishing curve and gradually made the digit less cursive, ending up with a digit very close to the original Brahmin cross. While the shape of the character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Drive-In EMC Test Chamber
Large means of great size. Large may also refer to: Mathematics * Arbitrarily large, a phrase in mathematics * Large cardinal, a property of certain transfinite numbers * Large category, a category with a proper class of objects and morphisms (or both) * Large diffeomorphism, a diffeomorphism that cannot be continuously connected to the identity diffeomorphism in mathematics and physics * Large numbers, numbers significantly larger than those ordinarily used in everyday life * Large ordinal, a type of number in set theory * Large sieve, a method of analytic number theory ** Larger sieve, a heightening of the large sieve * Law of large numbers, a result in probability theory * Sufficiently large, a phrase in mathematics Other uses * ''Large'' (film), a 2001 comedy film * Large (surname), an English surname * LARGE, an enzyme * Large, a British English name for the maxima (music), a note length in mensural notation * Large, or G's, or grand, slang for $1,000 US dollars * Lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recording Studio
A recording studio is a specialized facility for Sound recording and reproduction, recording and Audio mixing, mixing of instrumental or vocal musical performances, spoken words, and other sounds. They range in size from a small in-home project studio large enough to record a single singer-guitarist, to a large building with space for a full orchestra of 100 or more musicians. Ideally, both the Studio recording, recording and monitoring (listening and mixing) spaces are specially designed by an acoustician or audio engineer to achieve optimum acoustic properties (acoustic isolation or diffusion or absorption of reflected sound reverberation that could otherwise interfere with the sound heard by the listener). Recording studios may be used to record singers, instrumental musicians (e.g., electric guitar, piano, saxophone, or ensembles such as orchestras), voice-over artists for advertisements or Dubbing, dialogue replacement in film, television, or animation, Foley (filmmaking) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VentureBeat
''VentureBeat'' is an American technology website headquartered in San Francisco, California. ''VentureBeat'' is a tech news source that publishes news, analysis, long-form features, interviews, and videos. The ''VentureBeat'' company was founded in 2006 by Matt Marshall, an ex-correspondent for ''The Mercury News ''The Mercury News'' (formerly ''San Jose Mercury News'', often locally known as ''The Merc'') is a morning daily newspaper published in San Jose, California, in the San Francisco Bay Area. It is published by the Bay Area News Group, a subsidia ...''. History In March 2009, ''VentureBeat'' signed a partnership agreement with IDG to produce DEMO Conference, a conference for startups to announce their launches and raise funding from venture capitalists and angel investors. The partnership with IDG ended in 2012. In September 2009, Matt Marshall took on the role of executive producer for the DEMO conference. Over the years, a variety of companies have launched ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
