Talk:Waveguide (radio frequency)

message: SLAC defn:
A waveguide is an evacuated rectangular copper pipe. It carries electromagnetic waves from one place to another without significant loss in intensity--Light current 01:54, 31 January 2006 (UTC)
thread_title: Untitled

message: The sentence "A wave guide is used to guide waves" assures a non Scientist/Engineer will have no idea what the rest of the article is about.  Suggested change: A Waveguide is used to transport an electrical signal, prevent an electrical signal from leaking via radiation. Filter unwanted components of an electrical signal.
:It does clearly state electromagnetic waves, but it's true that guide is a bit vague. Filtering is not relevant. --catslash (talk) 22:48, 1 June 2009 (UTC)
thread_title: Vagueness of lead section

message: Hi all.  I'm just here disambiguating "Beam" and this isn't my field but the WG article TITLEs are a little muddled.  Might I suggest that:
*"Waveguide (optics)" be retitled "Waveguide (dielectric)" or similar
*"Waveguide (electromagnetism)" be retitled "Waveguide (hollow metal pipe :-)" or similar.
Reasons:
*It's all EM
*EM in fibers is often not visible
*Optical is also a general term refering to any EM bouncing around, e.g. GO, PO and BWGs (which don't even have a reference in WP!?)
I've drop this in Waveguide, WG(em) and WG(opt) as there doesn't seem to be much overlap between the "talkers".    Enjoy, Saintrain 18:03, 12 February 2007 (UTC)
replies: text: Hollow-metal-pipe versus dielectric, seems a reasonable split to me - see last two paragraphs of #Merger (above).--catslash 21:13, 12 February 2007 (UTC)

text: Um, why would we want waveguide hollow metal pipe? If anything, there should be 1 article about waveguides that includes the math required to analyze them. If a discussion of different geometries is needed than it should be placed in a section of that article. Gfutia 19:14, 19 October 2007 (UTC)
thread_title: Distinguishing between Optical, RF, EM and "Dielectric" vs "Pipe" WGs

message: I would recommend not merging the two pages together. Instead you may want to retitle waveguide (electromagnetism) to waveguide (RF) or waveguide (microwave). Optical waveguides are almost exclusively fiber optic based where RF/microwave/millimeter wave waveguides are almost always hollow metallic tubing. Two very different concepts. —The preceding unsigned comment was added by 199.46.200.233 (talk) 23:07, 15 March 2007 (UTC)
thread_title:  Merging 

message: I moved this to the talk page because it could be part of the article, but it was in the wrong place and there is not a place in the article where it could be dropped in.
It gives the solution for a particular wave guide, the hollow rectangular wave guide.  The article was discussing wave guides in general where it was.  If this was added to the article, it would need some supporting information such as variable definitions, probably a figure and needs to discuss that it pertains only to the one type of wave guide.  There is no place in the article that this could be dropped in without more work.    
With a Helmholtz below:
\nabla^2E+k^2E=0
using the boundary conditions of z (unlimited space) which can deduce a solve:
u(x,y,z)=(C_1\cos k_x x+D_1\sin k_x x)(C_2\cos k_y y+D_2\sin k_y y) e^{ik_z z}
and using the boundary conditions of x and y, inserting the standing wave equation:
\begin{cases}E_x = A_1 \cos k_x x\sin k_y y e^{ik_z z}\\
E_y = A_2 \sin k_x x\cos k_y y e^{ik_z z}\\
E_z = A_3 \sin k_x x\sin k_y y e^{ik_z z}\end{cases}\qquad \begin{cases}k_x=\frac{m\pi}{L_1}\\
k_y=\frac{n\pi}{L_2}\end{cases}
As we can know \nabla\cdot E =0 should be an another constraint equation. So for each (m,n) has two modes in it which are called TE and TM modes introduced below.
Constant314 (talk) 01:55, 15 January 2016 (UTC)
thread_title:  Recent additions, Helmholtz Equation 

message: I believe recent posts about the existence TEM modes in hollow wave-guides are using the terminology incorrectly or confusedly.  It is true that a propagating TE mode can be decomposed into the superposition of two plane waves, each of which is TEM to its own direction of propagation.  However, neither plane wave is a mode of the wave-guide because neither will satisfy the boundary conditions or the wave-guide.  Further, there is a statement that non-propagating TEM modes form the propagating TE modes.  If the TEM modes were not propagating, then it would not extend far enough into the wave-guide to form TE modes deep in the wave-guide.Constant314 (talk) 13:08, 6 May 2016 (UTC)
replies: text: I have written to you as requested and look forward to reading the article.  The particular words that were edited were not my words and I do not have any special attachment to them.  What has been written, appears, at least by my interpretation, to refute common knowledge about waveguides, hence my request for discussion. Constant314 (talk) 20:41, 6 May 2016 (UTC)
thread_title:  TEM modes in the hollow waveguide 

message: We should sacrifice the little space needed to present the mm values more accurately. I've just checked WR51 which is supposed to be 12.954 mm wide but is indicated as 13.0 mm.  — Preceding unsigned comment added by 153.92.184.111 (talk) 13:42, 28 November 2017 (UTC)
thread_title:  Accuracy of mm Dimensions in Table in "Waveguide in Practice" 

message: I think the answer is as follows (but I wouldn't stake my life on it).  In a TEM wave the components of curl d/dx Ez and d/dy Ez cannot exist because they a require a z component of E, and d/dx Ey and d/dy Ex cannot exist because they produce a z component of B.  That just leaves d/dz Ex and d/dz Ey which result in the E field varying along the length of the guide.  I don't think that can happen in a lossless guide with dimensions invariant with z.  Why don't you get the cited source from the Library if you think the statement is dubious. SpinningSpark 20:55, 13 March 2020 (UTC)
replies: text: I submitted the request.  Due to technical problems I will have limited connectivity for the next 7 to 10 days.  Please don't take my silence as anything other than communication difficulty.  Constant314 (talk) 00:47, 14 March 2020 (UTC)
thread_title:  TEM curlE=0 

message: It seems to me that the main subject of this article is the hollow waveguide, commonly shortened to just waveguide. I will make a redirect for it, but I suspect that hollow waveguide might be a better name for the article. Gah4 (talk) 20:35, 24 April 2020 (UTC)
replies: text: Yes, this is a common problem we keep coming up against on page after page.  When we started calling these things waveguides, microstrip, light pipes, finline etc just didn't exist.  Pages that were originally on a narrow subject get expanded and overcomplicated over time. SpinningSpark 00:04, 25 April 2020 (UTC)
thread_title:  [[Hollow waveguide]]