Posts Tagged ‘simulation’

Curtain Quad Panel Wifi Antenna 18dbi

Thursday, September 27th, 2007

Are You remember this one :


This looks very crazy, oddly promising 18 dbi gain.

BUT now there are more info about this, as promised by admin of the GUW forum.

Here is all info in spanish :

The author of this one is Ross Anderson and the original idea for this antenna is from 1984 year 🙂 the good thing is that all the information about this one is here.


There is interesting version of this antenna build by the author. On his site he describes the how to build this panel antenna from zing fence. The original 2400mhz version is here :

The idea and the info :

Here some pictures from the em simulation from GUW site :

18dbi wifi panel antenna

So as I see this, I can accept that this antenna works. On the site is said that this antenna outperform many commercial ones.

The diagram of this antenna and look from in front :

18dbi wifi panel antenna cheap homemade diy diapositiva5.jpg

More pictures of this antenna build and tested for 1296Mhz and 2400mhz :


Interesting about this is the using of speaker wire for matching transformer :

“… Solder a 1+ inch piece of speaker wire to the N connector. One wire goes to the center pin; the other wire to the outside part of the connector. I drilled a small hole in the connector flange for the wire to be inserted into and soldered in place. Leave about 3/4 inch of insulation on the speaker wire (as measured where the two wires are together). This is the transformer, transforming the antenna impedance to about 50 ohms.”

There is also PDF tutorial on the GUW site : guw panel 18dbi.pdf

So this is promising design which I should test soon too. Will be interesting to find out will this design works if it is printed on PCB?

Backfire Helix Feed

Friday, September 21st, 2007

First – I never made any helix antennas, nor spirals or anything similar. Consider this as warning 🙂 BUT in the HAM world spiral feeders used in dishes is something very often used.


Very simple – small spiral and reflector in front of the dish.

It looks like that in the spirals there are several modes endfire and the normal-mode. This modes are explained on the side, but more reading is needed. Also there is right and left hand rule in these antennas.

On the page is a NEC code witch may be useful to simulate this antenna.

Dimensions on the pictures are given for 2401MHz but the peak for this is around 2.3ghz so for tests whit wifi we must change dimensions a little.

If anyone have the references as PDF – do not bother to send them to me 🙂

more pics :


Slotted Waveguide Antenna Links and Software

Saturday, September 1st, 2007

All we know trevor marshal design – here is another approach in designing slotted waveguide. 😉

Firs thing is of course 10ghz book in chapter seven


Next thing is hlssa program :

Hlssa programs are used to design position of the slots over the waveguide surface.

There are several versions og this one in the net – hlssa54 is first one in German.

there is hlssa61e – version in English and as I support ver 61 isthe new one 🙂

Some links for hlssa program : – English version – pic – pic of antenna


Here some links that I found useful :

First :

Cut-off calculator for square waveguides :


Some pictures of simulations /these ones are NOT mine / :




Next there is applet in java which give us way to see what tm modes we have inside the waveguide based on freq and dimensions.



And finally a place where to choose standard waveguide tubbing –


So we have all thing needed to design our new waveguide for the frequency that we need.


This is just collection of links that You may find useful. This is not tutorial. But this is basic for beginning building slotted waveguide.If You are interesting there is a lot of reading in the net – Good luck!