# Talk:Power dividers and directional couplers

I have the feeling that
Low frequency directional couplers
needs more text. But I am unsure where to start.
The only sentence banging in my head is:
Winding direction are not drawn, because the device will function anyways, you just have to test wich port is wich.--Arnero 13:03, 11 June 2006 (UTC)

I removed this from the References section to comply with Wikipedia:Avoid self-references:
(When the original version of this article was created in June, 2006 it was nearly a copy of the "POWER DIVIDERS AND DIRECTIONAL COUPLERS" with changes to Wikipedia markup.) 
Art LaPella 04:07, 9 January 2007 (UTC)

Actually, I don't think that was a self-reference, it is talking about the main reference for the article, not the Wikipedia article (you should have just deleted the "with changes to Wikipedia markup" bit).  I cannot retrieve the original article to check, the link has gone dead, but if it really is copied this article is either a copyvio or should carry a note the the government document copied from is in the public domain. SpinningSpark 14:35, 4 June 2009 (UTC)
It is a Navy publication, and is therefore in the public domain. The article has changed a lot since the handbook was copied. I have found a new link and will update the footnote. --Jc3s5h (talk) 15:00, 4 June 2009 (UTC)

These should be included here. They are the simplest form of these devices.--ThrobbingTrousers (talk) 03:12, 4 June 2009 (UTC)

Resistive voltage dividers and the so-called 6dB hybrid (actually a resistive bridge) are not power dividers.  They are, in fact, power dissipators and do not really belong here. SpinningSpark 14:30, 4 June 2009 (UTC)

Modification on the formulae L2,1 and D3,4
Three performances of the coupler are defined as positive numbers : Coupling Factor, Isolation and Directivity. Because the device is a passive one, P3 < P1,  so 1 - (P3/P1) < 1 ad finally log (1 - (P3/P1)) < 0. This is why I proposed to insert a negative sign at the beginning of the formula
I would add the following formula P1 =~ P2 + P3 (neglecting P4).
For the directivity I would replace D3,4 by D4,3. The notation used for the other parameters imply that the first index corresponds to the output port, the second to the input port. This is not the case for the Directivity formula.
D4,3 = I4,1 - C3,1
Fred6531 (talk) 14:04, 26 October 2009 (UTC)

My apologies for reverting you out of hand.  Your edit was very similar to a previous IP edit which was just plain wrong and I assumed you were the same person without reading your edit too carefully.  I agree the insertion loss should be positive, but note the source has missed out the minus sign as well as our article - probably an error, but we should find another source. SpinningSpark 23:00, 26 October 2009 (UTC)

One of the major broadcast-equipment firms (I think Shively) has a nice set of white papers describing the design of large combiner systems based on hybrids and filter banks, and some of the significant design issues like group delay.  121a0012 (talk) 22:13, 18 December 2010 (UTC)

The ratio part of the insertion loss formula has recently been changed by a string of IPs from 1-P3/P1 to 1-P2/P1.  I suspect they really intended to change it to P2/P1.  Even this is wrong, the expresion is supposed to be for the ideal insertion loss caused by coupling off power P3.  The actual insertion loss in indeed P2/P1 but that is not what is required here. SpinningSpark 07:28, 16 March 2011 (UTC)

I have removed the proposed merge template.  The editor who inserted it did not start a discussion so it is unclear what was intended to merge.  The article is a one sentence stub that does little more than link to this article, essentially it is a soft redirect.  There is already way more information in this article than in hybrid coupler - there is nothing to merge and the proposal is moot. SpinningSpark 11:27, 7 June 2011 (UTC)

It seems like there is no need for the hybrid coupler page though. Should that page be deleted? DaffyBridge (talk) 01:16, 18 November 2011 (UTC)
No. It serves as an immediate answer for the person who knows about power dividers and directional couplers, and as a redirect for people who don't. Jc3s5h (talk) 01:42, 18 November 2011 (UTC)
In any case, we would not delete the page.  If we did anything it would be to turn it into a redirect.  It is already essentially a soft redirect.  The page is capable of expansion into a much more substantial article if anyone cares to have a go. SpinningSpark 08:34, 18 November 2011 (UTC)
I've made some of these. I don't recall any methods that are only applicable to equal power division; my recollection is all the methods could just as well produce unequal power division by tweaking a few dimensions. So I don't see the benefit of expanding the "Hybrid coupler" article. Jc3s5h (talk) 14:30, 18 November 2011 (UTC)
Agreed, and "coupler" in the article title implies just that.  Redirect to hybrid coil might be more appropriate and should satisfy Jc3s5h's objection.  The only additional useful thing that hybrid coupler has is a link to this article which could easily be transferred. SpinningSpark 16:13, 18 November 2011 (UTC)
Hybrid coil is not a suitable redirect for Hybrid coupler. See http://www.microwaves101.com/encyclopedia/hybridcouplers.cfm
In the nomenclature I'm familiar with, hybrid couplers are a ring built on a printed circuit board, where the trace on the board forms a transmission line that is one wavelength in circumference (so they are only practical for microwaves). Ports are attached at various points depending on the phase shift desired for the outputs. Jc3s5h (talk) 16:47, 18 November 2011 (UTC)

I believe the term "hybrid" originally related to transformers but was then extended out to other kinds of couplers, initially only 90° couplers were included, but now the term is all-embracing.  What everybody seems to agree on (including your own ref) is that only 3 dB couplers count as hybrids. SpinningSpark 18:10, 18 November 2011 (UTC)

This review is transcluded from Talk:Power dividers and directional couplers/GA2. The edit link for this section can be used to add comments to the review.
Reviewer: Nathan2055 (talk • contribs • count) 17:16, 5 September 2011 (UTC)


### The chart
I have fixed an obvious typo in the hybrid transformer section, please be more specific if there is anything else you think needs addressing in the section.
The story with the {{cn}} tags is that I added these myself when I reviewed the article pre-GA but was reluctant to delete them outright as I am fairly sure (from professional knowledge of transmitters) that the statements are accurate.  I will contact the editor who added them asking for a source.  I have already attempted to source them myself but with only partial success.  I will have another look at the weekend (right now I am on the road and do not have access to my library) but if nothing turns up I will remove or rewrite the unsourced parts. SpinningSpark 19:09, 5 September 2011 (UTC)
I would have fixed the typo myself, but it was so bad I couldn't make out exactly what you meant. If you can source those three statements I'll pass the GA. --Nathan2055talk - review 19:43, 5 September 2011 (UTC)
Oh, and why didn't you merge those images to the Commons? I'm just curious, wouldn't that allow more people to access them? --Nathan2055talk - review 19:50, 5 September 2011 (UTC)
See here SpinningSpark 17:17, 11 September 2011 (UTC)
I have added several new references and reworded or deleted the parts I could not source.  I have left messages for the original contributors but have had no response.  They are welcome to restore with sources anything I have deleted: I am sure it was all technically and factually correct.  I have also made a couple of small additions to the lede: this was to address a comment in the previous GA review.  I believe that all items have now been addressed. SpinningSpark 17:17, 11 September 2011 (UTC)
Great! Someone placed a use Dmy dates template-but I'm unable to find a problem. The article passes! Congratulations! --Nathan2055talk - review 21:08, 14 September 2011 (UTC)

Power dividers and directional couplers are also used in integrated photonics but there is no mention of this.  — Preceding unsigned comment added by 137.222.75.139 (talk) 11:19, 7 October 2011 (UTC) 

Just a comment (kind of important).  The hybrid couplers when used as combiners should show +3dB, not -3dB.  The math DOES show the addition, but the labels are not correct.  — Preceding unsigned comment added by 63.233.111.114 (talk) 00:11, 22 May 2018 (UTC)
It's still a −3 dB coupler regardless of which way round it is connected. SpinningSpark 08:14, 22 May 2018 (UTC)

The first paragraph could be more understandable to someone unfamiliar with the subject. Various ports are mentioned but without explanation of what they are.  — Preceding unsigned comment added by Quicknick5k (talk • contribs) 09:22, 20 May 2022 (UTC) 

It seems likely that this paragraph would be opaque to the uninitiated. A few thoughts:
It should be stated that the device has 4 ports
The first use of port could perhaps be changed to port of the device
The terns input port, output port, coupled port and isolated port could be italicized to clarify that the ports are being given names.
The term output port should be changed to transmitted port for consistency with the rest of the article
The word couple[d]] is used a couple of times other than in the designation coupled port, which is surely confusing; coupled (diverted) perhaps?
catslash (talk) 00:44, 21 May 2022 (UTC)
@Catslash: Those all look like good improvements to me, except perhaps the last one.  That just seems to be adding confusion to me.  The use of the word coupled in a generic sense is unavoidable in this article and adding (diverted) as a disambiguator on every occurence is both clunky and not really solving the problem. SpinningSpark 08:55, 1 June 2022 (UTC)
The explanation in the Notation and symbols section is perhaps clearer than that in the lede. catslash (talk) 22:12, 1 June 2022 (UTC)

In the General resistive bridge hybrid section, a symbol of a common-mode choke with a curved arrow appears in two figures. I am unable to determine the meaning of this feature; textbooks sometimes use a curved arrow to label the mutual inductance between inductors, but it's not labeled here (and the solid core, and description as balun or CMC, already implies strong coupling). Maybe it's vestigial?
I gather the original author isn't around to comment anymore, but, perhaps someone in-the-know can add explanation in text, or edit the SVG accordingly? 98.144.229.53 (talk) 14:53, 30 May 2025 (UTC)

It seems that the unnumbered figures are not originals by Spinningspark, but rather derivative works (perhaps based on fig. 19) by Sufficient statistics (or simply original works of Sufficient statistics).  Yes, the curved arrows are probably vestiges of those used to label mutual inductance (as in fig. 7), and should be removed.  Perhaps Sufficient statistics can fix this - otherwise it shouldn't be too difficult to edit the .svg files. catslash (talk) 23:27, 31 May 2025 (UTC)
Good point. I have removed these curved arrows. Sufficient statistics (talk) 05:19, 1 June 2025 (UTC)
Thanks for the quick fix.  The curved arrows are gone, and it wasn't even necessary to clear my browser cache. catslash (talk) 14:51, 1 June 2025 (UTC)
For future reference: you are allowed to take a file from Commons, edit it to create a derivative work, and then upload this derivative work to Commons.  For example, I created Maxwells fish-eye lens.svg by editing 0x30114's Luneburg lens.svg (which I transferred from WP to Commons for the purpose).  The only restriction is that you must release the derivative work under a license that is allowed by the license of the original (the original license demanded share alike, so I simply used the same license).  I don't recall the technicalities of uploading such a derivative work, but no doubt the upload wizard will guide you through it. catslash (talk) 17:03, 1 June 2025 (UTC)

I am trying to find where on Wikipedia the common TV cable splitter is described. It should be here, but I am not actually sure if it is, and if it is, it doesn't say so. Gah4 (talk) 07:26, 27 October 2025 (UTC)

See the Applications: Hybrids section, second paragraph, first sentence. catslash (talk) 18:46, 27 October 2025 (UTC)

So, the figure 16 version? Part of the reason for the question, is that the figure is so far from the paragraph describing the use. I remember seeing the inside of the usual 75 to 300 ohm adapter, with one or two turn coils on a ferrite core.  I am not sure I remember the insides of the splitter, with the 10 turn coil. Gah4 (talk) 22:41, 27 October 2025 (UTC)

Sorry, I did not read the question properly; the article mentions the TV cable splitter, but does not specifically describe it.  Yes, at UHF the hybrid coil would seem likely for an equal split into two. catslash (talk) 00:29, 28 October 2025 (UTC)

Can we make that a little more obvious in the article?
OK, I changed it to mention figure 16.
Also, this one is similar, but the resistor is in a different place. Gah4 (talk) 03:27, 1 November 2025 (UTC)