high gain WLAN antenna??

[winglj]

Hi, everyone. Do you have any idea about the high gain WLAN omni-directional antenna available in the commercial market?

It seems it is only a monopole/dipole like antenna, why its gain can be so high? Any information or reference will be welcome.

 

[Azulykit]

You don't cite the antenna you are questioning.

I suspect that the question is how can one have high gain and omnidirectional coverage?

In reality you cannot. What is generally implied is that one can narrow the elevation pattern and thus increase gain while keeping the pattern in the horizontal plane omni directional.

This can be achieved with a co-linear array of dipoles (along k or the z axis). The more dipoles the greater the gain. "Franklin" antennas are one example.

 

[winglj]

Hi, thanks for your reply. Actually the high gain omni-directional "tube/whip" antennas I mentioned about can be found in these website:

http://www.hyperlinktech.com/web/omnidirectional_marine_antenna_hg2409um.php

http://www.hyperlinktech.com/web/hgv-2404u.php

http://www.hyperlinktech.com/web/hg2412u.php

There are more examples by just searching "high gain antenna WLAN" in google.

They look like monopole/dipole, but it must be some design inside. Any information about that will be appreciated.

 

[jallem]

That antenna is called a collinear antenna, see
link below and search for collinear antenna in
Google: **broken link removed**

Other way:
http://cheatthezone.tripod.com/wireless/colinear.html

Using patch antenna:
www.urel.feec.vutbr.cz/RADIOENG/2005/05_04_040_042.pdf

They are "ONLY" omni-directional in the azimuth plane just
like a dipole is.


See also patent: 6771227

 

[mahojazz]

hi winglj,

all commercial high gain antenna are achieve through lengthening the dipole antennas. you would have noticed that they are much longer than the ones you get preinstalled in your router. But there is a drawback with these high gain dipole. if you need coverage of 2 floor, the upper floor coverage will get a hit. This can be observed by the radiation pattern. So it may not solve your problem to achieve better coverage.