Posts Tagged ‘half wave’

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.

All pictures are from this page :

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.


Dimensions :


And feeding point and tune stub :


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 :


Some more pictures :

omni antennaomni11.jpg

11dbi SMC Panel

Sunday, May 13th, 2007

First I wish to say that I build and tested this antenna, and I was SURPRISED – how this small device is able to work so good! This small antenna outperform my other two homebuilt 14dbi wifi panels.

I used two one sided pcb to create this, but on the zero forum there are pictures where only thin metal sheets are used, and it works again.

The diameter of the circle is equal to the half wave light of the 2.4ghz wifi band or 62mm , so this antenna may be recalculated for other /5ghz/ frequencies.

Now antenna INFO :

Name of Antenna, model : SMCANT-DIFP11

Data sheet can be found on this link :

Frequency : 2.400 – 2.500 GHz
Gain : 11 dBi
VSWR : < 1.22
BEAM WIDTH • Horizontal: 70° • Vertical: 70°
DIMENSIONS • 25 x 102 x 102 mm


So here is the interesting part – this one is found disassembled on



Link to the forum



Very small! Great results!

Dimensions of the reflector are 105×105 mm

8 mm gap between two metal plates of the “circle” and the reflector.

Here are my test whit this antenna – the original test was for other but I need something to compare :

Here is the way to stack two of these homebuilt antennas together :