Posts Tagged ‘dbi’

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.

Sector Antenna GRAD2487

Friday, September 28th, 2007

This is interesting russian antenna. Small sector antenna, gain is only 10 to 12 dbi.

Sector Antenna GRAD2487

From this site I can find that the price of this is nearly 200 euros or 260$ !!!

Quick specifications :

Frequency band   2400-2483 MHz
Gain   13 dBi
Maximum input power   100 W
Power distribution diagram  
  • Horizontal: 90°;
  • Vertical: 18°;
Impedance   50 Ohm
Standing wave coefficient   1,5
Mast mount diameter   35-60 mm
Weight   1.8 kg
Size, L x W x H   250x160x360 mm
Maximum wind speed   160 km/h
Polarization   Vertical
Operating temperatures   -40° … +50° C
Connector   N-Type female
Additional information   Input is DC-circuited

In the russian forums for a lot of antennas this last “Input is DC-circuited” is very critical ! There is some sort of fanaticism about this 🙂 may be the weather there, I’m not sure why.

Here is link to some pictures of the interior from here :


What we have under the fiberglass hood – strong plate which hold connector, coax line to the one pcb plate whit four printed dipoles.

The design of the dipoles is very interesting to me – I sow this dipole design several times :


You can find dimensions of this antenna whit lot of pictures forum.

I’m not completely sure why this antenna is so interesting to me.

You can search in google for “printed Dipole Antenna with integrated Balun” and will find something very similar to the upper pictures. So design is well known and used from manufacturers.

Here some links :

printed_dipole_design2_600_396.jpg printed dipoleprinted dipoleprinted dipole

On these examples balun is madded whit hole trough the plate or “via hole” , but on this antenna we do not have a hole.

BUT without this hole I cannot see this “Input is DC-circuited” thing! Where they close the loop?

Here I find something very similar only multiplied by four for creating omnidirectional antenna :


And finally one more picture on which we have similar dipole and feeding :


For final this is very complicated antenna extreme hard to be reproduced without proper materials, equipment and software tools.

This shows very professional design whit a lot of variables and places which need to be tunned. For me this antenna is impossible to be built at home.

DIY Hi-Gain Antenna on Cheap ;)

Friday, August 31st, 2007

Very Cheap Dipole feeders – they are easy to be build and you do not need a lot or expensive materials. Everything here can be made from wire or scrap /I watch too much scarpwars on Discovery channel 🙂 /

I found some very interesting looking feeders for dishes – VERY cheap to make, first is made only from feeder line 🙂 or simple coax.


A simple dipole feed. Good solution to illuminate parabolic constructions (solid, grid etc.) Heliax holds the dipole, as well as feeds the N-type female connector to the back. Tests shown 4 dBi (against Lucent 24 dBi parabolic grid). “

Second is Russian of course

Name of the file is interesting too D_Linc3_008.jpg


Interesting materials – onli several pieces of pcb board are used – very good.

From the same forum are these too –

d1.jpg d2.jpgdipole_construction.gif

Last pic is from

And for the end howto make wire reflector or DIY Parabolic Grid Reflector

diy reflector

Info is from this :

19dbi gird blueprint :

19dbi gird blueprint

For me is easy to buy small offset dish – 80cm is around 10 to 15 Euros here.