All WiFi users are constantly wanting more powerful signals. In this instructable we demonstrate how to build a simple but power double bi-quad WiFi antenna.
Parts List
A single-sided copper clad PCB sheet - I found a 20x10cm sheet with an incomplete circuit printed on it but not etched. The print was cleaned off with wire wool.
A length of 1mm diameter bare copper wire - I found a length of mains cable and removed the earth wire.
An N-type chassis connector and an N-type to SMA adaptor.
Four nuts and bolts for attaching the N-type chassis connector to the PCB.
Drill, soldering iron, solder, pliers and your favoured nut and bolt tightening tools
Your WiFi adaptor. I use an Alfa awus036h.
For my other projects see - http://www.ecopunk.org.uk/p/projects.html
Parts List
A single-sided copper clad PCB sheet - I found a 20x10cm sheet with an incomplete circuit printed on it but not etched. The print was cleaned off with wire wool.
A length of 1mm diameter bare copper wire - I found a length of mains cable and removed the earth wire.
An N-type chassis connector and an N-type to SMA adaptor.
Four nuts and bolts for attaching the N-type chassis connector to the PCB.
Drill, soldering iron, solder, pliers and your favoured nut and bolt tightening tools
Your WiFi adaptor. I use an Alfa awus036h.
For my other projects see - http://www.ecopunk.org.uk/p/projects.html
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Signing UpStep 1: The Antenna
Here we see a close-up of the antenna. A hole has been drilled into the PCB to accept the N-type chassis connector. Note the sheet of plastic. My initial thought was to shied the plate from the antenna but subsequent experiments have shown no change in signal strength so you do not need this plastic shielding.
You can also see the antenna constructed from the 1mm earth wire. You need to bend the wire so that it forms the diamond pattern as in the photo. Each side of the diamonds are 30.5mm. At the crossovers the wire does not touch itself.
One end of the antenna is soldered to the N-type at a height of 15mm from the collector plate. The other end is attached to one of the bolts holding the N-type chassis connector in place.
You can also see the antenna constructed from the 1mm earth wire. You need to bend the wire so that it forms the diamond pattern as in the photo. Each side of the diamonds are 30.5mm. At the crossovers the wire does not touch itself.
One end of the antenna is soldered to the N-type at a height of 15mm from the collector plate. The other end is attached to one of the bolts holding the N-type chassis connector in place.
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I have since moved on to a Yagi, for which, I will produce an instructable in the future.
Thanks for posting to this Instructable as it has made me want to improve my hardware.
I have retired my Bi-Quad and started to build a Yagi.
Thanks.
You can build bigger collectors with many elements on them and then link the elements together. You will need to do a search for larger bi-quads.
http://www.youtube.com/watch?v=rBBKSk627BM&feature=related
http://www.engadget.com/2005/11/15/how-to-build-a-wifi-biquad-dish-antenna/
A personality on another forum told me that he has achieved 175 miles with his biquad in ideal conditions. Though I expect that to be an overstatement, I still will be expecting to see most of the APs in my small city of 100k people so it should be pretty noisy..
I am also researching converting everything (including my Alfa) over to type F connections for universality. I understand that 50 ohm is the RF standard so I figure 50 OHM connectors and a very short length of 400 series coax cable will do the trick.
I will report my findings in a few weeks.
Peace
I think all the long distance connections are set up rather than random finds. In other words the claimer is optimising both ends; maybe a high-power AP (possibly with a dish at that end too) and then searching only for that AP.
I can get about 40 APs, in my street alone, with my current setup. The number of open and WEP APs is very small. Time to cast the net wider.
Your suggestion makes perfect sense regarding both ends being dish equipped. I'd bet that the AP had a unidirectional amplified feed as well, and possibly from a higher elevation to a lower on a fair weathered day.
The dimensions of the bi-quad antenna are matched to the wave length of WiFi and would not work with HSPA.
You would have to make an element of different dimensions.
If you Google "hspa bi-quad" you will find information. Much of it vague and not in English.
Read the literature on WiFi biquad. Determine why the dimensions are what they are for WiFi and scale to HSPA wave-lengths.
before I buy N male to RP-SMA male ...
I will be building a parabola by using a giant umbrella and I was hoping to use this as an nlb to it, how small can I get when I build a bi-quad you think? 5cm x 5cm?
thanks
As far as the bi-quad is concerned, the bigger the better. Also the more elements the better. I have seen much bigger with many more elements.
thank you !!! really good job :)
I use it on my DD-WRT repeater and in my car whilst War Driving.
Use the bi-quad as an LNB on a satellite dish and you will probably get many miles for your bucks.
The laptop I'm using now is connected by WiFi to a dd-wrt router acting as a repeater, which itself is connected by WiFi to a router about 60 meters away.
The repeater router has my bi-quad in place of one of the stick antennas. Works perfectly. The repeater router would not pick up the main router with just stick antennas.