# confusion about vertical polarization and horizontal polarization

Discussion in 'Wireless & RF Design' started by donut, Jun 22, 2012.

1. ### donut Thread Starter Member

May 23, 2012
51
0
Could you please help me to understand some basic concepts about antenna polarization. The books I have are really confusing and do not have examples that I can learn from. This is really frustrating because books are biased to people who have experience and not have any experience like me.

Please look at the attached E plane radiation pattern image I attached (figure 13).

The books image (figure 13) tells me that the attached image is a E plane radiation pattern which means that the E field is perpendicular to the earth (so vertically polarized).

The books image (figure 13) tells me that the attached image dipole is located on the line from 90 degrees to 270 degrees.

How can you have a vertically polarized antenna with a dipole positioned horizontally (90 degrees to 270 degrees)?

Figure 19 (attached) clearly correlates to horizontal polarized dipole but figure 13 says that it is a vertical polarized dipole.

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2. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
790
Presumably 0° / 180° is the ground plane angle. So the dipole is offset from the ground plane by 90° and lies along the 90° / 270° axis perpendicular to the ground. Rotate the page by 90° and that should represent "reality" as you would perceive it standing on the ground and looking at the dipole.

3. ### vk6zgo Active Member

Jul 21, 2012
677
85
Yes,you are confused!

Fig 13 is ,if you could imagine it,looking down on a horizontally polarised
dipole.

In other words,the diagram is showing you the radiation pattern in azimuth ,not elevation.

My understanding is that polarisation is not determined by the orientation of the E-field.
If this is the book I think it is,this is covered earlier

Actually,I was confused too,the E field orientation does determine the antenna's polarisation.
I got E & H fields mixed up,but the other stuff in this posting is correct.

Fig 19,in my opinion,not a very good diagram,simply shows that a vertically mounted dipole will have vertical polarisation,while a horizontally mounted dipole will have horizontal polarisation.

Unless I miss my guess,the book is the ARRL Antenna Handbook.
It's a great book,but it does have a fairly messy layout,so you may find diagrams that seem related,just happen to appear together,or the Fig referred to on one page may be on the next or previous page.
The "Digest" type format,where a lot of the stuff is slightly modified articles from "QST" tends to lead to these problems.

PS: Looking at the dipole diagram from "end on",the radiation pattern looks like a circle,instead of a figure 8,& looking at it from an angle,it looks like a doughnut.
The following website has a PDF which includes (fig3.1) a graphical representation of this doughnut shape.

http://www.ictregulationtoolkit.org/en/Document.3643.pdf

Last edited: Aug 10, 2012