sexta-feira, 16 de janeiro de 2015

Omnidirecional WIFI Antenna 6dbi

Thursday, September 6th, 2007

This one is very interesting design. I was used something VERY similar before time and all that I remember is, that it defiantly WORK fine, but it is pain to tune this.
This antenna is combination from usual J Pole antenna and Franklin array antenna /AMOS antenna only onmidirectional /.
Gain of this omni antenna is around 6dbi, but you may add more by adding more sections. Double the sections to add 3dbis.
omni-6.jpg
Dimensions :
omni6-dim.jpg
And feeding point and tune stub :
omni6-sec1.jpg
Some suggestions :
First CHECK dimensions of Your antenna.
Second : Matching to the feed-line is archived by sliding the connection of the feedline back and forth along the stub until an SWR as close as possible to 1:1 is obtained.
Third : Try to add quarter-wave ground plane.
Four : You can bend the half wave section to a half circle to be able to use small diameter of plastic tube :
close_2j.jpg
http://en.wikipedia.org/wiki/Slim_Jim_%28antenna%29
Some more pictures :
omni antennaomni11.jpg

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