Step 7: Connect the Antenna to the Wifi Modem

This is the most difficult part and depends on the electronic hardware you have. please read this step carefully. 

The basic idea is that you need to solder a wire between the WiFi board's RF output and the driven element of the yagi antenna.

But USB WiFi modems come either with an internal antenna or with an external antenna. Those with external antennae, like mine, are easier to connect because you are just replacing the external whip antenna with the Yagi. Those with internal antenna may need to have their on-board strip antenna modified as illustrated in the pictures here. You need to slightly experiment in this case.

I have tried soldering a coax to my board's antenna connectors and the two ends of the yagi's active element loop but it did not work in my case. I have no explanations why that did not work, but other DIYers that have built Yagi antennae connected their antenna in this manner.

In my case, I just connected a single thin strand of copper wire between the active element of the strip antenna and one end of the loop of the driven element.

Please read the annotations of the pictures for more details.

Okay well I read through the entire post and I saw many things that made a lot of sense, also saw a lot of unnecessary flaming, but I do have a few comments to make. Right off the bat the one individual that asked about having his modem in the basement with a rotating antenna on the roof needs a reality check. Overlooked in the connecting the USB dongle to the antenna was the transmission line length, for these frequencies it should be as short as possible and a multiple of 1/2 wavelength I'd suggest as close to 2.41 inches as one could manage (use a small diameter 50 ohm coax). Take the dongle apart and connect a USB extension cable to it and mount it directly on the antenna assembly. Paper clips vs copper, at this frequency it's not going to make much difference, however the specific model was generated using 14awg copper. Someone said glue it all to cardboard then cover it with more cardboard actually a strong and stable design, original author said build around popsicle sticks(wooden), both are subject to absorbing moisture from the air and either can have a poor dielectric constant, I would suggest some kind of plastic (they make popsicles with plastic sticks). The lengths of the elements, the spacing between them, and keeping them all in the same plane and parallel to each other is the most important consideration. The driven element, #2 in this design: that one I would make from 14awg copper, I'd make a simple dipole rather than a folded dipole, I would take two pieces of wire make 90 degree bends in them cut the bent part to about 1/8 inch and attach my transmission line. Take a piece of heat shrink cut two notches in it about 1/4 inch apart and insert the wires into it and shrink it, maybe reinforce the space in the center (break a tooth from my comb and stick it in the middle before heating the shrink?) cut it down to the correct overall length and insert it last. If you use the folded dipole make sure the folded part is perpendicular to the plane of the rest of the antenna and use 300 ohm twin lead to connect to the dongle, but your SWR will probably be much higher, reducing your effective gain and possibly resulting in early failure of the dongle. Horizontal vs vertical, after you have your antenna connected and have connected to some network you can try rotating it about its horizontal axis to see if you can get a better aspect on the other antenna (more bars). All in all though good job to Biotele, it's cheap, it's easy, and if done right will provide excellent results. I did not build this antenna, but I built 2 antennae very similar before reading this post, My son and I live almost 2 miles apart and either of us can stream 1080p movies from the other's house during a thunderstorm.
<p>I think you could make an instructable out of all that :D</p>
<p>The way the paperclips are connected to the device is not clear. It seems they are just glued on a pieace of wood with no wire and no connections. I am missing something? </p>
<p>Two questions. First, how can I fix it if the scale is not correct? I think they are the same relative distance apart, but it doesn't match up to the mm listed on the printout.</p><p>Second, could I use this on the router as well, or is it only to boost the receiver located at the computer or device? Thanks!</p>
<p>Think I will make one..but use a piece of 1/2 CPVC pipe for the spine rather than wood sticks. Think it will look nicer and be more weather resistant as well.</p>
<p>Hi - I think the greeen pad is the USB Wifi modem ?</p><p>Thanks to have details and possible suppliers</p><p>Regards</p><p>Baboo</p>
<p>Can someone make a schematic? That would help us who need to visualize it.</p>
I think the reason your original antenna hookup didn't work was the geometry of the driven element. For a clear explanation see http://makeprojects.com/Project/Homemade-Yagi-Antenna/623/1<br> She builds a larger Yagi, but the principles are the same. Neat ibble, though.
it is working with one wire driving the loop.
<p>It would work better if you connected the ground plane of the antenna to the ground of the transceiver though the shield in the coax. It probably didn't work for you because you hooked it up to the wrong place on the loop.</p>
<p>what people don't realize is the &quot;cantenna&quot;, (pringles can antenna) is really just another Yagi, this one is an optimized antenna with different construction</p>
<p>Thank you so much for sharing this!</p><p>:)</p>
<p>Can this be used in a wifi reciever?</p>
<p>Okay... yes it can.</p>
<p>If I could connect a second router as a wireless access point could I replace the antenna with this or is it just for recieving? This is all quite over my head but im pretty sure i could do the build something out of paper clips part. Ill have to read this all again more thoroughly later.</p>
<p>Hi there, can somebody please help us, ... we have an issue at our rural property (not too rural but) where our 3G smart phones work okay outside but inside a timber framed house with a metal roof they don't work at all, we were told to install a Yagi 850 MHz Antenna outside on the roof and the shortest cable possible into the house with a phone cradle, which then makes the phone not mobile and stuck in one place, <strong>it is legal to buy and overseas mobile repeater</strong> , so can somebody please tell me if this would work, ...placing a Yagi Antenna outside, with a smaller car antenna attached to the other end inside - would the small car antenna acts as a repeater inside ?? we cant afford the ridiculous price tag the 2 telcos are offering for their smart repeaters (over $1000) so was wondering if this is a ridiculous idea or not??.</p><p>apparently if we are receiving a good signal outside the house (4G and 3 G) then we would have no problems inside the house.</p><p>Regards Anthony </p>
<p>Your idea won't work. You will have to buy a repeater. But be aware that getting a better signal for a cell phone can be a difficult. The best thing for you to do, regardless of what country you live in would be to google Wilson Antennas and then call then and explain the situation. </p><p>The repeaters have several antenna options. You have to have two antennas . If there is only one cell tower in your area then you can use an omnidirectional antenna high and low. If there are two or more towers then you will need to install and orient a directional antenna to null all but one tower. Where you place these antennas will have a huge effect on your results. </p><p>A repeater system will not get you a strong signal. It may get you a signal that will work. Cell phones are incredible sensitive. If you can operate your cell phone reliably outside you should be able to get it inside with the repeater, but not necessarily in the whole house. The repeater will not get you a large operating area. Some say they will, but they are basing this on ideal situations witch do not exist outside a testing setup</p><p>If you buy a Wilson cell phone repeater and it doesn't work the chances are you have installed the wrong antennas or the antennas are in the wrong position. You are going to wind up paying $400-$500 US. </p><p>Oh, in the US the cell phone people managed to get law passed that says you have to tell them if you use a home repeater. They have no way to tell if you are unless you do tell them. </p><p>Don't expect too much. If you just need a good strong signal in one room then they usually work fine. If you want a strong signal everywhere in your house then they don't work so good. The key is the outside antenna. That weak signal that your cell phone won't work on, is also too weak to amplify. There is also the chance that the signal is so low that no antenna can pick it up. Most cell phones have a signal strength meter, open it and walk around your property. If you can't find at least a signal level below 110 db (lower is better) then the repeater won't work. You don't have to understand what a db is just that lower is better. If the signal fluctuates when standing still the repeater won't do you any good either. In other words if you can't find a place where your cell phone will work on it's own, then a repeater won't work either. </p><p>A repeater works by you being able to put it's outside antenna in a place where there is a signal (that will actually work with the bare cell phone) then amplifying that signal and redistributing it using another antenna. A weak but usable signal outside will get you a somewhat stronger signal inside. A strong signal outside will get you a good strong signal inside with wider coverage inside. </p>
<p>I think for the internal antenna to act as a repeater you'd need a device to power it and transmit that signal. Maybe the thing to do is buy the Wilson powered device for your carrier's 3g frequency. Plug it in to the outdoor yagi and indoor antenna and that should do it, as far as I know. But I'm pretty sure that situation you're describing would need some power input to make the repeater work.</p>
<p>looks like an old school TV antenna to me </p>
<p>That is a Yagi. </p>
<p>My problem is going through a wall and then a floor. I'm lucky to get 10mps from a 30mps connection. I'm using a D-Link DWA-130. It has an extension with a 45&deg; angle base. It seems the best position is the face of the unit aimed toward the router in the basement. A bit of aiming and draping of wire is needed. Is it possible to build an aluminium foil bowl to focus or bounce the waves into my unit. Just a thought.</p>
<p>So I have a question for all you more knowledgable types. I purchased a external wifi adapter to go with my homemade yagi, and unfortunately, i purchased the wrong type of connector for my antenna (purchased a coax cable with male SMA connector instead of a RP-SMA connector). My question is, is it necessary for me to connect the shield and the inner conductor to each end of the driven element, or do i just need to connect the inner conductor?</p>
<p>Aaaand I think i figured it out. Didn't read the annotations of the third picture. </p>
<p>i read the annotations and i still didnt figure it out :-)</p>
<p>nice, but it is unclear to me wher you solder yr antenna. 'the active element of the strip antenna' and the 'driven element'<br>Ok the driven element is the round paperclip, but what is the 'active element'<br>and what do i solder on what? does the core go to the active element and the shielding to the driven element? or the other way around?<br></p>
<p>Will Legal size paper be long enough?</p>
<p>For those with limited experience making antennas, and to keep from having to open up the WiFi router and soldering wires, it would be far easier to just get a USB gain antenna and connect it to your computer. You would have to install a software driver on the computer, but this might be easier for a lot of folks.</p><p>In one case the gain antenna is attached to the WiFi router and internal antenna on the computer, and in the other the gain antenna is used by the computer and the regular antenna is used by the router. There is no hardware modification to the computer, only software. And of the two antennas, the one in the computer is usually the weakest link. I have a usb antenna and when I use WiFi in my shop with the laptop the signal is very weak and intermittent. With the usb antenna connected the signal is 3-4 bars. </p><p>If you are trying to increase the range of several surveillance cams then the yagi on the WiFi router won't work anyway, since it is so directional it can only be pointed at one device. And to use it with your laptop you will have to use the laptop in only one direction. The direction the antenna is pointed towards. The usb antenna on the laptop on the other hand will allow you to change positions. </p><p>If you're trying to connect several surveillance devices through a router to a computer, it might be better to get a WiFi repeater(s). Then place them between the surveillance devices and the Wifi router. And then if the signal is still weak to a laptop location use either another repeater or a usb antenna. The usb antenna is usually cheaper. </p><p>If my humble opinion the best use of a high gain Yagi antenna is to steal a signal. Much easier to just drive a little closer. LOL</p>
<p>This is fantastic. So what about with an existing yagi antenna -- would I be able to get additional gain/directionality by adding more directors/elements (at the appropriate lengths and distances? For example, this one: </p><p><a href="http://bcbj.org/antennae/lte_yagi_diy.htm" rel="nofollow">http://bcbj.org/antennae/lte_yagi_diy.htm</a></p><p>Would making it a couple of feet longer improve the gain?</p>
<p>The gain of a yagi does increase with additional elements, but cannot be increased much beyond about 17 db. So about 11 elements is max. Also there are multiple links giving the length of the elements and spacing, so it would be much easier to just cut the elements using a caliper and mark a ruler or other piece of beam material for the spacing and drill a hole slightly smaller than the elements and push them through. Using a printer to print the antenna is a little bit iffy. The beam can be almost anything, since the dipole elements have a null in the middle. They can be attached to a piece of stiff wire, but considering the size a plastic or wood ruler would be ready made. It's also ok to shorten the antenna by leaving off a few elements. A yagi with just 4 or 5 elements will likely be all that most folks need. Each additional element adds a diminishing increase in gain. </p><p>If you really want to maximize gain, make two, four or eight 11 element beams and phase them. Two phased together (parallel) doubles the gain, four quadruples and eight doubles the four. </p><p>Solid copper hookup wire stripped of the insulation would be easier to cut. </p>
<p>Can I simply glue my existing little wifi antenna into the spot for the driven element and make it work?</p>
Why inkjet
Can I connect this antenna to my nrf24l01 module
<p>Great job, I'm digging out some fiberglass tubing from the supply scraps to use instead of popsicle sticks, you definitely motivated me to try this out.</p>
<p>I tried to built it but step 7 is so hard so my usb was damaged , but any where this was amazing topic and I appreciate your effort . any way I get a professional wifi antenna from chines store with very cheap price and high gain , that is it </p><p>http://link.cashat.pro/158m5me</p>
<p>Should I use A4 paper or letter size paper?</p>
<p>ya welad el metnaka 7ad yerod 3ala den omy :D</p><p>plz reply me </p>
<p>what are the dimensions between every metal piece </p>
<p>Please Help me , My problem is that how to connect coaxial cable to router. I made the antenna with a long piece of plastic. I plan to connect it via coaxial RG-6 F to my router because SMA and N type connectors are not available in my place. I also made a balun with folded coaxial (like a horseshoe) so that the impedance mismatch may be rectified. My router has a fixed antenna( photo attached).The router has only one antenna solder point but the coaxial have central wire and outer braiding. Do I need to connect both or only the central element. Any help would be appreciated.</p>
<p>wait so your not supose to connect any of the other paper clips</p>
<p>thanks your a life saver</p>
Please provide better pictures, I can see absolutely nothing here...: Step 7: Connect the Antenna to the Wifi Modem, first picture. Which wire goes were? <br>
I did built this antenna, but it does not work. There is absolutely no gain. Instead it is worse then before. <br>It is also not clear how you need to solder the antenna to the board. One wire, two wires?
Hi Having made the antenna how or what do i need to connect it to my laptop to increase the extra antenna power, Kind Regards Brian UK
Hi, I thank you very much for the reply about the antenna wiring it is more clear now that you have explained, Kind Regards Brian UK
Hi can the wires from the yagi antenna be connected with the wires in a a usb connecter and connect directly into my laptop. kind regards brian
If you mean just soldering a USB connector on to the feedline for this antenna, no, that won't work. You still need something to handle the actual generation and reception of the wireless signal. <br> <br>However, if you mean connecting the antenna to a USB wireless adaptor, that's possible, provided you connect the feedline from the antenna to the antenna connector on the wireless adaptor. If the adaptro doesn't have one, you'd have to tear it apart and find where the internal antenna was connected.
If you mean just soldering a USB connector on to the feedline for this antenna, no, that won't work. You still need something to handle the actual generation and reception of the wireless signal. <br> <br>However, if you mean connecting the antenna to a USB wireless adaptor, that's possible, provided you connect the feedline from the antenna to the antenna connector on the wireless adaptor. If the adaptro doesn't have one, you'd have to tear it apart and find where the internal antenna was connected.
Can i use a wire if so what is the diameter. Thank you<br>
Of course, it has to be stiff and solid. I don't think it has to be exactly a certain diameter. Maybe someone with antenna theory can enlighten us further.

About This Instructable


1,086 favorites


Bio: Make a better Instructable, and the world will beat a path to your website.
More by Biotele: Easy to Build WIFI 2.4GHz Yagi Antenna Hand Cranked Flashlight Mod plus Joule Thief Ganzfeld: Hack Your Brain the Legal Way
Add instructable to: