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Antenna Design - More Options


Drewdroid
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Updated with more sources - 03/10/2012

After Darren had posted the Mk4 Pineapple Urban Assault Mod, I started wondering again about concealed antenna options with high-gain possibilities. I've not come to any definitive conclusions but started looking at the circuit board patch antennas which led me to fractal antennas. (I guess it's the Ham operator in me) I'm going to test some of the fractal designs as well as some patch antennas. Keep in mind that the enclosures will definitely affect the antenna tuning. Even just a layer of plastic can shift the frequency response and make it less efficient. This is where designing the antenna comes in handy. You can also take the knowledge below here and use it to correct for your enclosures.

I've started this with the hopes of coming up with a good community guide for antenna selection and options for increasing the pineapple range. Yes, there's plenty of high gain antennas such as the yagi and parabolic but sometimes we want to be a bit more discrete. Please keep in mind that what you end up using could be considered illegal by the FCC if you output too much power. What I'm hoping for is as follows:

A) A list of antennas that you've tried either commercial or DIY

1)cost and construction

2)actual gain compared to what was marketed

3)environments tested in such as urban, heavy foliage, rolling hills, rocky terrain etc. with a description of line of sight

4)actual db readings of before/after

B)Links to resources you've found and any designs you want to share

c)overall opinion of your various antennas and types of WiFi hunting scenarios such as omnidirectional/sniping/combo and how they work for that purpose.

D)how well would the antenna blend in if left in place somewhere

E)Possible pictures along with pineapple for scale

Some resources I found so far in my searches:

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=22298 Design and material types selection guidelines

http://fermi.la.asu.edu/w9cf/yagipub/index.html Yagi antenna modeler software to scale up or down and get perfect measurements of elements and location

http://jcoppens.com/ant/helix/calc.en.php Helical antenna calculator

http://www.dxzone.com/catalog/Antennas/WiFi/

http://www.andrewhazelden.com/blog/2011/02/homemade-sierpinski-gasket-fractal-wifi-antenna/

http://www.qsl.net/n9zia/

http://members.fortunecity.com/scienziatopazzo/fractalantennas.htm

http://www.jpier.org/PIERC/pierc16/03.10062206.pdf

http://www.orbanmicrowave.com/The_Basics_Of_Patch_Antennas.pdf

http://highfrequencyelectronics.com/Archives/Mar09/HFE0309_Tutorial.pdf

http://archive.rocketreviews.com/reviews/all/scratch_patch_antenna.shtml

http://colinkarpfinger.com/blog/2010/the-dropouts-guide-to-antenna-design/ - Awesome guide and intro to designing/testing antennas

http://www.n5ebw.com/2008-09/antenna-solutions-on-the-cheap/ Images of a patch antenna and Yagi antenna both on etched on circuit boards

http://www.qsl.net/n9zia/wireless/appendixD.html - Bi-Directional 2.4 GHz One Watt Amplifier With Receive Pre-Amp

http://www.iw5edi.com/ham-radio/?building-a-2.4-ghz-10-el.-yagi,115 Building a 2.4 GHz 10 element Yagi

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=12603 slotted waveguide antennas - Unidirectional & Omnidirectional High gain, Simple construction

http://www.trevormarshall.com/biquad.htm Very simple and compact Bi-quad design

http://www.ti.com/lit/an/swra350/swra350.pdf 2.4 GHz YAGI PCB Antenna compact and VERY Flat - 100 x 150 mm.

http://www.instructables.com/id/Easy-to-Build-WIFI-24GHz-Yagi-Antenna/ Slightly Ghetto version of Yagi using popsicle sticks - but the theory and measurements are sound

http://www.ab9il.net/wlan-projects/wifi6.html another wood and copper Yagi

http://www.instructables.com/id/Bi-Quad-WiFi-Antenna/ Double Bi-quad antenna

http://www.ab9il.net/wlan-projects/wifi3.html Interesting helical coil attached to satellite dish collector - apparent 26dB gain!

http://www.ab9il.net/wlan-projects/wifi3A.html simple helical antenna with better gain than bi-quads

Edited by Drewdroid
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Having built antennas for Ham radio, I'm cautious about DIY without an analyzer. (the Analyzer I have stops at 150MHz :angry: ) Dialing in the SWR, impedance and resonant freq is what makes them work *right*

Granted an HF rig cost a bit more then a WiFi adapter ;)

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Having built antennas for Ham radio, I'm cautious about DIY without an analyzer. (the Analyzer I have stops at 150MHz :angry: ) Dialing in the SWR, impedance and resonant freq is what makes them work *right*

Granted an HF rig cost a bit more then a WiFi adapter ;)

Anode, I definitely agree with needing a good analyzer but the prices for the nice ones hovering around $3k or so is definitely cost prohibitive. I'm hoping some of the members will have contacts with universities with RF labs or possibly work contacts that can lend some time to properly test. I've been trying to find designs that have been fully tested to work from as a basis. Throwing a shout out to other hams is a good way of tracking down equipment as well. Some of them have more disposable income to be able to get all the bells and whistles along with just doing ham activities versus all around hacking of things and software.

The thing is to not let us get discouraged. I had a friend that was astounded when I built a bandpass sub enclosure by using pen and paper to do the spec design back when they were still a new idea. He insisted it was a miracle it worked as efficiently as it did. Common sense and some good basic knowledge can get us mostly there with antennas. For the true optimum performance gains we need the tools to tweak them. Look at how Marconi started out in the late 1800's.

Another thing I wanted to bring up for everyone is that just because you've got the range to receive the signal doesn't mean you'll get back there. We need to make sure our send gets as far as our receive. Without that balance we've got a great listening device at the far ranges and that's not what we're looking for here.

73, KB1JPW

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I burned up all my disposable income on a Kenwood TS-2000, icom 7000, and a Kenwood THD-72 :) But at least I'm set for a while (or until Dayton! Got my tickets, not sure if I'm going or not. hope to get a customer foot the travel bill)

Having kinda poo-poo'ing earller, I'm still gonna play with some yagis / stacked yagis. I guess best route is modeling software (because we always live in perfect conditions :) )

But I do have a Asus 9db omni (with the cool airfoil shape) and a Hawking 12db directional (HA12W) I like a lot. I'll do a little more research with them and pull up some real numbers (as best I can)

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I wanted to add an antenna that I had disassembled for internal use - it's one from this N300 Wireless PCI Adapter

http://support.netgear.com/app/products/model/a_id/2605

The internals, although split for MiMo workings show how tiny they can end up being. The traces are on both sides of the board and are setup for frequency ranges covering B,G and N. It's an example of an antenna tuned for 2.4 GHz and 5 GHz bands.

2012-03-08_20-29-23_548-1.jpg

The ground is going to the ground plane traces - far side of the pcb in the picture (which is actually the "front" of the antenna)

The positive is going to the near plane traces. Notice how they are mirrors of each other and the center trace is thinner on this side to make up for the extra distance added. They both have the same trace surface area.

For scale, a standard business card covers all three of those antenna elements.

I'm going to run a few signal tests on an individual element and try to get back with some hard data.

Edited by Drewdroid
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Guys, what do you think about this DIY Classic Paper clip Antenna? expected gain up to 9 dBi.

I think it might work but I'm not sure about the gains. It's small enough for sure to fit anywhere but I'd worry about the measurement of the elements.

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That biquad primestar dish antenna works pretty good. I used a gladware sandwich container for a radome. http://www.trevormar....com/biquad.htm Very simple and compact Bi-quad design

I've also built a "toothpick" omni which worked very well. Looked like a grappling hook.

I'm not a fan of the pringles cantennas, but a Malibu rum can works pretty well.

Edited by barry99705
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