You can read about this antenna here www.g0mrf.freeserve.co.uk
Freq : 5.6Ghz Gain : 10Dbi Beamwidth : 55 deg
All building instructions are on the site.
You can read about this antenna here www.g0mrf.freeserve.co.uk
Freq : 5.6Ghz Gain : 10Dbi Beamwidth : 55 deg
All building instructions are on the site.
Goggling early in the morning some time give me some very interesting results π
This time is this thing – helix antenna whit reduced dimensions.
http://www.vtnews.vt.edu/news_print/index.php?relyear=2005&itemno=899
This thing have gain: 12dBi and dimensions only 165mm light and diameter of a dish 165mm
link : http://www.hitel.it/default3NSD.asp?tree=108&usr=-1&codlingua=1&grc=4&grl=16
Here You can find some patent info: http://www.patentmonkey.com/PM/patentid/5986621.aspx
On the net there is a lot of info I thing : http://scholar.lib.vt.edu/theses/available/etd-11242003-123529/unrestricted/Barts_etd_CH4.pdf
and also good article about traditional spirals http://scholar.lib.vt.edu/theses/available/etd-11242003-123529/unrestricted/Barts_etd_CH3.pdf
Here You have experimental build and testing of several of these antennas π
http://scholar.lib.vt.edu/theses/available/etd-11242003-123529/unrestricted/Barts_etd_CH7.pdf
Google is a great thing π
Horizontal Polarized Omnis are mystery for me π . Anyone was seen open vertical polarized omni for wifi. Whit horizontal ones there is another story. Except slotted waveguides /these works great/ , but they are really big things.
Here is one idea for horizontal omni or “double helix antenna” :
http://hft.uni-duisburg-essen.de/amateurfunk/amateurfunk_en.shtml
Mast is used for reflector for for this one. Ant in the internet there is a lot of designs for spiral antenna. Difference here is that is used dual spirals. Coaxial line is hidden inside of the mast, and its look like that feeding point is on the bottom of the antenna.
One more link – there was calculator for this antenna on that treat : http://wireless.com.pt/forum/index.php?topic=15786.0 but now I cant find it.
Thanks to the rt_rex You can find calculator on this site : Omni Helix XLS
I hope that soon we can see some results and tests of this antenna.