Posts Tagged ‘swr’

2.4Ghz Yagi Antenna for WIFI – using single sided PCB board

Friday, October 5th, 2007

I don’t like Yagi antennas /sorry/, and I never try to make one , but this look interesting – it is only one side pcb design that differ from the most dual sided similar.

On the side is said that this antenna is a clone to a commercial one, but not a name or model is mentioned.

The dual sided board is needed to make the feeding point of the yagi antenna – here we have something very interesting and different to be able to make all needed parts on one sided PCB board. In fact this is dipole.

Link to the page :

Here is schematic :


Here some pictures whit dimensions :




On the second picture You can see haw to assemble the dipole – this is the interesting part. This antenna is feeded by dipole not whit loop like most Yagi antennas. Here they make a balun whit the stripped coax and the pcb board.

There is also one aluminum disk used to hold the board that is used as reflector :


On the site is said that this antenna have 11.5dB gain. And for last there is a SWR test for this antenna pretty good results I thing :


The peek is little out of wifi band but we still may get very good results for wlan applications.

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