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antenna
antenna
antenna A device used in radio astronomy to detect radio waves; also known as an
aerial. In an antenna, radio waves induce an oscillating electric current in a conductor. The simplest antenna is a
dipole antenna, which is a simple metal rod. More complex antennas, such as the
Yagi antenna, may consist of a dipole or folded dipole (the
driven element) with other conducting rods (
parasitic elements) which direct or reflect the waves on to the dipole and so increase the antenna's
directivity and
gain. The most powerful radio telescopes, especially at high frequencies, use parabolic (dish) antennas to collect waves and bring them to a focus. Large numbers of antennas may be combined in an
array to achieve high resolution. Antennas may also be used to transmit radio waves.
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Antennas America, Inc. Licensed by DIRECTV(R) to Manufacture its new Freedom(TM) Antenna System
PR Newswire; 7/14/1997; 700+ words
; ...over-the-air antennas, the Company offers the WALLDO(TM) Antenna as an alternative...complete line of antenna and related systems...planar array flat antennas for indoor and outdoor...well as conformal antennas designed for smaller...provides custom antenna designs and ...
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Antennas - parameters and definitions. (antennas for electronic warfare applications)
Magazine article from: Journal of Electronic Defense; 9/1/1997; ; 700+ words
; ...starts a series on antennas for EW applications...been tossing around antenna parameters in earlier...for various types antennas, provide a guide...matching the type of antenna to the job it must...Functionally, any antenna can either transmit...signals. However antennas designed for ...
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GNSS antennas: an introduction to bandwidth, Gain pattern, polarization, and all that.(INNOVATION)
Magazine article from: GPS World; 2/1/2009; ; 700+ words
; ...specifying a GNSS antenna. We explain...properties of GNSS antennas in general...coverage, all GNSS antennas share the same properties. GNSS Antenna Properties A...However, such an antenna cannot be built...world" GNSS antennas see a gain roll...
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Antennas: highly visible and hardly visible.
Magazine article from: Journal of Electronic Defense; 5/1/1999; ; 700+ words
; ...takes very long antennas. The VLF antenna is a trailing wire...communications antenna ever designed...phased-array antennas and is being fabricated...will probably have antennas. * You can't hide an antenna by covering it with...
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Antennas: critical links in the wireless signal chain.(Cover Story)
Magazine article from: EDN; 6/6/1996; ; 700+ words
; ...uncomfortable dealing with antennas, which, in EMI/RFI...against it. Yet, good antennas, or "aerials," at...are vital. The right antenna can increase performance...matching let you realize an antenna's maximum potential...Although it may seem that antennas, like wallpaper patterns...
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Antennas: Where the rubber meets the road; Handset market demands low-cost volumes, sophisticated innovation.(Spotlight)
Magazine article from: RCR Wireless News; 11/12/2007; 700+ words
; ...key mantra in the antenna component space. Antennas need precious room...another mantra-main antennas now have a second, backup antenna to ensure that...design their own antennas, made by volume...own designs go to antenna specialists and...
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Antennas for electronic warfare systems.
Magazine article from: Journal of Electronic Defense; 8/1/1990; ; 700+ words
; ...for testing of the antenna and radome performance...The forward and aft antennas each provide transmit...decoy. The transmit antennas can easily handle...levels. MULTIBEAM ANTENNA SYSTEMS Multibeam antennas at Raytheon ESD use...
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Antennas Direct Partners with TV Stations to Inform Viewers About Antennas.
News Wire article from: PRWeb; 6/7/2009; 700+ words
; ...widespread. That's why antenna manufacturer Antennas Direct partnered with broadcast...channels using a better antenna." About Antennas Direct As a member of the...advances in television antenna design, Antennas Direct continually tests...
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 "Winnetka Talk (IL)")
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Antennas pose no hazards, doctor claims
Newspaper article from: Winnetka Talk (IL); 5/22/1997; 700+ words
; ...companies for more antennas, so they have decided...moratorium on new antenna construction. The...installation of cellular antennas. The rules state...construction of an antenna. At the May 13...by a cell phone antenna are non-ionizing...produced by one of the antennas is relative ...
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QFHA antennas for satellite radio and mobile phone applications. (Technical Feature).(Satellite radio and mobile satellite phone systems require quadrifilar helical antennas)
Magazine article from: Microwave Journal; 7/1/2002; ; 700+ words
; ...beneficiaries of these antennas. The mobile satellite...require a similar antenna mounting on the...based on helical antennas, A single helical antenna is capable of...on the helical antenna design. Although single helical antennas require a relatively...
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antenna
Book article from: The Columbia Encyclopedia, Sixth Edition
...the design of the antenna; the transmitting antennas of a radio station...theoretically, the same antenna can be used both...instances transmitting antennas are designed differently...signals on a small antenna element. Phased array antennas, used for long...
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Antenna
Encyclopedia entry from: The Gale Encyclopedia of Science
Antenna An antenna is a device used...infrared light. Antennas mediate between...reach the bowl (antenna), and are electrically...space. The horn antennas used for microwave...stationary. Rotating antennas usually operate...stations. Often, an antenna will include a reflecting...
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horn antenna
Book article from: A Dictionary of Astronomy
horn antenna An antenna in the shape of a flared horn. It...feed at the focus of a parabolic antenna. The cosmic microwave background was first detected with a large horn antenna. Horn antennas have very low side lobes and are...
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antenna temperature
Book article from: A Dictionary of Astronomy
antenna temperature A measure of signal strength in radio astronomy...same signal power as the source under observation. Antenna temperature is a property of the source, not of the antenna itself. Where a uniform extended source fills the telescope...
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parabolic antenna
Book article from: A Dictionary of Astronomy
parabolic antenna A bowl-shaped aerial with...bowl; also known as a dish antenna . At the focal point is a...High-performance parabolic antennas are often of the Cassegrain...principle of a parabolic antenna is identical to that of the...
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