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The line: "For computers, it's used the de facto standard Mcx cable." is not just bad english, but also probably very POV as there are lots of different cables used for antennas (The link points to a company called MCX Inc!).
The reference "Understanding electromagnetic fields and antenna radiation takes (almost) no math", by Ron Schmitt, EDN Magazine, March 2 2000 is linked to a host that is not related to the publisher (very useful article, by the way). Since the article is freely available on the EDN website, shouldn't the link be made to that page? Here is a direct link: http://www.edn.com/article/CA82250.html That page contains a link to the PDF version, which is the same as the one currently linked.
The June 2009 Antennas and Propagation article addresses only magnetic dipole antennas, but the conclusions apply to electric dipoles by the symmetry between electric and magnetic fields. It gives a tighter upper bound for loop antenna band widths. Magnetic materials help by lowering H for a given B.
Antenna vs. aerial?
Is there any difference, either technical or (obviously) etymological, between the two terms?
Are they exactly equivalent? Or are there cases (parabolae?) where one might refer to part of an overall system and the other to the entire device, including reflectors etc.?
Is there a historical and geographical slant to their distinct use?
- My sense is that American English uses antenna and rarely uses aerial. American English may also have a distinction that an aerial is made from wires. An wikt:aerialist performs on high wires. Looking at wikt:aerial noun confirms those distinctions are made. Glrx (talk) 00:54, 9 June 2013 (UTC)
In my experience (in America), the terms are more or less interchangeable, but aerial is less common, or perhaps antiquated. However, books show that they appear to have had distinct meanings originally. Read about it. Dicklyon (talk) 02:09, 9 June 2013 (UTC)
Is this confusing?
The intro states- In each and every case, the transmitters and receivers involved require antennas. The list immediately preceding includes Radio Astronomy as a use of antennas. The transmitter antenna may be hard to define in that case. — Preceding unsigned comment added by 18.104.22.168 (talk) 04:04, 17 June 2013 (UTC)
- It didn't say that each use required both a transmitting and receiving antenna. There are a variety of research fields like radio astronomy and meteorology that use receivers and receiving antennas to pick up natural radio signals that are produced by the environment. By the way, radio astronomy does use transmitting antennas on occasion. A number of the largest radio telescopes have been used to do radar surveys of nearby planets like Venus, in which the dish sends out a powerful microwave signal which bounces off the planet and is received by the dish again. The microwaves can penetrate the dense cloud cover of Venus as light cannot, to produce a map of the surface. --ChetvornoTALK 09:51, 17 June 2013 (UTC)
Antenna converts electron movement into photons
Its not disruptive editing. There are hundreds of reliable sources that says the carrier of all EMF is the photon and that photons have dual wave particle properties as defined by the theory of quantum mechanics one of the most accepted models of subatomic physics. Thus, an antenna converts electron movements in the antenna into radio frequency photons. — Preceding unsigned comment added by 22.214.171.124 (talk) 14:22, 10 November 2013 (UTC)
- Your addition will be confusing to people because antennas are not analyzed that way. Because the energy of the photons is so small the operation of an antenna is completely classical. The photons radiated by a television transmitter have an energy of 10-26 J and would be extremely difficult if not impossible to detect. We also don't describe a transformer's action by saying the primary and secondary exchange photons, and we don't describe how a hammer exerts force on a nail by saying it exchanges virtual photons with the nail, but of course it does. --ChetvornoTALK 14:58, 10 November 2013 (UTC)
- All the sources I've ever seen describe radio frequency phenomena in terms of Maxwell's equations and approximations derived from them. If radio frequency phenomena are to be described in quantum mechanical terms, find a reliable secondary source that specifically discusses radio frequency antennas in quantum mechanical terms. I regard it as original research for a Wikipedia editor to attempt to apply quantum mechanical descriptions of phenomena at optical and shorter wavelengths to radio antennas. No doubt a qualified person (not a Wikipedia editor) could write such a description, but I don't know if it would turn out to be only theoretical or whether it would be experimentally verifiable. Jc3s5h (talk) 19:21, 10 November 2013 (UTC)
- Reliable sources could be found; I found some. My point above is that it is not OR to describe the emission of radio waves by antennas using photons, it is misleading and UNDUE weight. Like all of classical physics, the functioning of antennas is at base quantum mechanical and could be described, as the IP suggested, in terms of the antenna's "energy levels" and radio photons. A process is called "classical" if the energy levels are too close together to measure, so the energy can be considered a continuous variable. Or equivalently if the individual photons are too low in energy to detect individually so the electromagnetic field can be considered continuous. From the Planck relation the energy of radio photons is between 10-21 and 10-26 J, far too low to measure, so an antenna operates completely classically. So describing the antenna as emitting photons is not technically untrue but is misleading, as it implies that antennas are not classical and are analyzed by quantum methods, like the emission spectra of atoms. --ChetvornoTALK 17:46, 22 November 2013 (UTC)