Talk:Cage aerial

There is no single type of antenna called a "cage aerial". This article lumps together a number of antennas that already have their own articles. A monopole mast cage antenna, the main type this article covers, is called a Folded unipole antenna. A cage antenna in the shape of a "T", as in the picture, is called a cage T antenna and is already discussed in that article. A dipole antenna in the shape of a cage is called a cage dipole and is discussed in that article. This article may be a WP:POVFORK or just redundant, but either way it needs to be merged. --Chetvorno^TALK 00:43, 14 March 2023 (UTC)[reply]

Yes, there is a connection, but a cage antenna is not a folded unipole; the two different antenna types look similar but (at least in some unipole modes) have electrically distinct modes. Do not dare try to merge the articles. See No no no no NO below.

— Astro-Tom-ical (talk) 04:35, 23 April 2023 (UTC) (K7TLI)[reply]

Thanks for catching that. I agree it shouldn't be merged into Folded unipole antenna, a folded unipole is not a cage antenna. I was in a hurry and didn't look at the Folded unipole antenna article closely enough. Instead it should be merged into Monopole antenna and Dipole antenna. Cheers --Chetvorno^TALK 21:33, 25 April 2023 (UTC)[reply]

Under no circumstances should a cage antenna (or cage element) article be merged with the folded unipole antenna. Like many superficially similar-looking antennas (large loop / halo / small loop; half-loop / half square, both called a Π antenna; center-fed dipole / Carolina Windom; fan dipole / bow-tie antenna) the two antennas are electrically dissimilar.

The clearest distinction I can think of is that a cage element in a vertical or horizontal antenna always has no current running through its center, and usually has no center-line. A folded unipole always has net current flowing in the mast (its "center wire") in a direction contrary to the net current flowing in the outer skirt wires; it only can radiate when those two currents are unbalanced, usually managed by contriving a resonant path that excludes either the central mast or the skirt.

It is part of the design & configuration of the skirt wires that directs the majority of the current to flow either on the inside mast or outside skirt wires, and only in the particular case that one has managed to convince the unbalanced current that it would rather flow on the outside that the unbalanced antenna currents simulate a cage antenna. It is one of the operational modes of a unipole, but the unipole can still be adjusted to operate as a mast radiator, in which case the skirt wires act more like a multi-gamma match than a cage.

A folded unipole always has the need to design-in some way to unbalance the currents in the mast and the skirt wires. A quarter-wave vertical cage antenna never needs any such considerations: There is no central current to unbalance.

It is indeed a very insightful to observe the connection between the two different antenna types, but then again, many antennas are visibly very similar but electricialy different. Steer clear of the folded unipole article.

Astro-Tom-ical (talk) (K7TLI) 04:17, 23 April 2023 (UTC)

Just as a suggestion, what might suit you instead would be to rewrite this article as Antenna cage element or similar: Just going over the benefits of using a cage element instead of a single-wire element, and providing several real-world examples of where it's been done. I would claim that what you folks have noticed as a problem in the article is that there isn't really a distinct cage antenna: It's rather that antennas can have their vertical (or horizontal) single wire elements converted into multi-wire cages in order to simulate a "fat" wire or cylinder. Rather than just using a cage element in one kind of antenna, you can use a cage element anywhere you could have used a single wire.

(And as a technical point, I think that it might be a design mistake to make the capacitive, non-radiating horizontal element of an antenna into a cage: My first impulse is that the cage wires should be arrayed in a single flat layer, in order to maximize capacitance to ground. Although there's a lot I don't know; there could be some practical reason to want a horizontal cage that I'm not familiar with.) (But I do dismiss being able to spin in the wind: It should be guyed to not spin.)

Astro-Tom-ical (talk) (K7TLI) 04:55, 23 April 2023 (UTC)

@Astro-Tom-ical: Okay, I agree, the folded unipole antenna is a shunt-fed monopole, not a cage antenna as this article is covering. I didn't look at the unipole article closely enough. --Chetvorno^TALK 19:57, 25 April 2023 (UTC)[reply]

As you point out above, there isn't really a category called "cage antenna", there are cage versions of monopole antennas, dipole antennas and maybe other types. As you mentioned, wire elements of thin wire antennas can be replaced by cages, to increase the bandwidth, or decrease the radiation resistance of end fed dipoles. I feel that, rather than a separate article on Antenna cage element which is not a WP:COMMONNAME and will be harder for readers to find, cage versions of antennas should be covered in the existing article for that antenna type. So I suggest this article be merged into Dipole antenna and Monopole antenna. There is already mention of cage dipoles in Dipole antenna. --Chetvorno^TALK 19:57, 25 April 2023 (UTC)[reply]

@Chetvorno: Well, your common-language argument is legit, but I'd say that "cage" is the common term; perhaps the article should be "cage (antenna)". "Element" is just something I tacked onto "cage" prevent my writing from being ambiguous. Your proposal to augment individual articles seems sort of reasonable, but I tend to fret that there would be a lot of duplication between articles: To my knowledge, 'T', 'L', monopole, and dipole antennas have all been made in cage form and published in QST, RadCom, or the ARRL or RSGB Antenna Books; that's at least four distinct articles that would need to have their shared content kept in sync. It seems better if they all could be linked into the common material kept in a single separate article about cage elements, to avoid redundant information and the typical deterioration of shared content (for example, compare the English language antenna tuner article to all / any other language version).
Astro-Tom-ical (talk) 02:04, 28 April 2023 (UTC)[reply]

My opinion is these articles still have to have content on cage radiators, whether or not there is a separate Cage aerial article. The thickness of the element affects several properties of a monopole or dipole element, the resonant length ("end effect"), the bandwidth, the input impedance and therefore the feed arrangements. It appears in the equations. I am doing a rewrite of Monopole antenna (see User:Chetvorno/work6, criticism welcome) which includes these factors, and it wouldn't make sense to omit the cage monopole which is used when a thick element is needed. The same applies to Dipole antenna. Cage T antennas are a common type of T antenna, and are included in the article; to remove them would leave a hole. Also, as you noted, the effect of a cage element is different when used for a capacitive topload than when used for a radiating element. The logical place to discuss this is the Monopole antenna article, which has a separate section on the important subject of capacitively loaded monopoles.

So it seems to me having a separate Cage aerial article is redundant, in addition to the fact that the term "cage antenna" is not used in antenna literature. There is no mention of the term in Balanis, Kraus, Johnson & Jasik, Carr & Hippisley], Kumar, Stutzman & Thiele, Volakis or the ARRL Antenna Book --Chetvorno^TALK 02:44, 2 May 2023 (UTC)[reply]

From discussion in section Talk:Cage aerial#No no no no NO: Bad idea above, changed merger tags to propose this article be merged into Monopole antenna and Dipole antenna. --Chetvorno^TALK 23:20, 7 May 2023 (UTC)[reply]