How to Make an Active Wifi Tetrapak Antenna - Fast & Cheap Way ...

... & get an awesome directional client m.Usb-TetraRex" 14dBi antenna ...

... this is just one model of mine *SpikeAnTenna"* series & my first instructable here and some day will follow maybe also a second one, an addition to this to enhance its range/gain even further :-) ...

a good wifi UsbKey + a longer Usb cable, some juice tetrapak, some paper masking/duct tape, some thin cardboard, superglue, seizors, blade cutter & some basic skills making a "metallic" cardboard 13dB enhancer from a certain tetrapak ...

- First you need to find a proper WLAN Key with (best!) internal smd ceramic chip antenna onBoard properly positioned inside the plastic enclosure, something like on first slide ! IMHO best choice is a Netgear-WG111T (retail western edition) regarding price/performance ratio with Atheros chipset ... A Netgear-WPN111 has a similar construction ...

- Worse but still OK (you loose approx.1dB of gain) are those like older and about a third cheaper Netgear-WG111 (plain, retail) with a microstrip (PCB) straight front-up lined antenna like on next two slides : 2nd & 3rd . This pics are from both side of that Key. I believe (but I am not sure), the same is with a cheaper Netgear-WG111TEE (OEM eastern Europe edition), correct me if I am wrong.

- other types of microstrip antenna designs (M or V or T shape etc.) onboard a Key are not too suitable (you loose 2dB or more of a gain); tipical example is a newest & cheapest (last 3rd Ver.) of Canyon CN-WF518 (Turbo) or Asus-WL-167g, which can not be positioned properly inside thru bottom of a Key Enhancer (Canyon, the first version had a chip antenna, the 2nd was like Netgear-WG111_plain & 3rd is No good at all to use with tetrapak enhancer thru bottom mount!). These type of not suitable ones are represented on next two slides /4th & 5th/ ...

- also UsbKeys with 2 chip antennas like D-Link-DWL-G122 /diversity onBoard / or one same type but diagonaly soldered inside a Key are not too suitable, but can be used, maybe with some mods .. so before you buy, try/check construction with maybe some borrowed Key first, like I did (with the upper first one!). The last - 6th slide shows this kind of a Key part inside ...

Now is the time to find also a proper fruit juice tetrapak (not all are suitable for best result!) in a mall and prepare it to became "the signal Enhancer". It is a thin cardboard+ALuFoil+paper+PlasticFoil "brick like shaped" & compressed together stuff, but with Flat & almost square compact bottom & a square look like "piramidal" cone on the top with an open tap !!! ... Most suitable is new undamaged like the one on a down photo. It is a 2 litre Pfanner juice enclosure with 9,2x 9cm square bottom and approx. less than 23cm high flat sides. The juice costs less than a dollar ... Tetrapaks are usualy made of layered cardboard with embedded layer of thin aluminum foil, which acts as metal housing/shield inside ... I found also a similar local juice enclosure, but a bit different measures (a bit wider & shorter also 2 litre), but it would not perform so good as that mentioned before ...

An empty and inside washed & dryed tetrapak is now to be a base of an Enhancer. First you have to mark a bottom center of it with a marker & draw a rectangle shape future hole for a Key tight thru future bottom insertion around that center. The hole has to be drawn with a larger side up & perpendicular to the tetrapak wider side at the bottom (92mm) ; best to use thicker/overlaid bottom tetrapak side for hole. Also the center of a hole HAS TO BE offset down for about one cm (and a mm or two maybe to the left) regarding to the center of a tetrapak bottom. This way, a hot tip of a Key internal chip 1dBi antenna will be positioned right at the center axis of a tetrapak, when inserted properly later ...

After cutting a hole with a blade cutter & checking if the Key passes smoothly but tightly thru the hole, it is the time to cut the top of a tetrapak. Use same blade cutter first to ged rid of only the the cone and then seizors to edge/smooth the sides of an opening ; get rid of any residual opening imperfections w/o shortening sides ... The sides will be now approx. 22,5cm high ...

... is to make a small cardboard "oval" about 2cm deep tube type Key holder with some added "side holding wings", so take about 3cm wide enough long 0,5mm thick cardboard piece & wrap it around the Key to get a shape & maybe use some sticky tape to glue it around, keeping the tube shape. Take out the UsbKey (so do not glue the cardboard to tight around it) & cut out 4 of the "tube" 1cm side wings & spread them out @ 90-deg angle; remove/cut the wings leftovers on the tube. So you get a 4 leaves "daisy" shape Key holder to glue it (I used superglue) w/o a Key to a tetrapak bottom hole. When the glue dries, you can insert the Key later. The bottom of the antenna with inserted Key than should look like this somehow on the 1st photo ...

Her is also a 2nd-next (unfortunately not sharp) photo of the Netgear-WG111T Key I used for this antenna with some remarks (chip antenna is this side facing with hot tip up) with proper orientation for vertically polarized signals. Thats why is good to know the inside Key construction, for this type of antenna. So I needed to open it to give you proper info; chip antenna is located 7mm inside back from front plastic cover tip ...

Ps.: if using a plain Netgear-WG111 instead of my recommended T version, it has to be fliped axially for 180deg to mach the same signal polarization as the T version ; so with cheaper one the Netgear logo will be seen facing instead - 2nd slide ...

Finished antenna w/o a stand looks like this from backside (pointed to the AP with vertical signal polarization) on a first slide and frontside view on the next ...

Inner side view of the mounted Key, clearly shows its offset position, if carefully checked. The front tip of a plastic Key enclosure is pushed/situated 37mm (for this particular Key) from inner bottom of a tetrapak, which is practically antenna back "metal" reflector; so the Keys chip antenna hot tip is situated right in the middle & 30-31mm (wifi 1/4-WL) away from the bottom of the finished enhancer, which represents a WaveGuide 1,5-WL long at higher wifi channels ...

The antenna is quite directional & extends Keys range for about 4 times or a bit more in open non-obstacled distance/view ! The range of this basic setup can be extended even further ... but about that in a maybe new Instructable some day later ! ...

Since the tetrapak has quite thin sides, w/o the original top cone tends to deform by time & antenna square front opening later gets more romboid shape, so is good to prevent that, since that spoils the antenna performance. Maybe by gluing outside close to its end some outside plastic isolated copper wire or cardboard/plastic made additional shim ... For some other purposes I hardened the structure with some thicker cardboard outside antenna like on this last photo ... but it does not to be so long like on the slide ... That should be all for now ... :-))

... but if anyone is interested more in other ways of boosting a range of these days non-expensive wifi Usb Keys or other my wifi antenna projects, can visit this link and browse further inside also for other linked wifi antenna projects : wifi USBkeY range Enhancers-boosters 4 Dummies ... well, is not written in english, but in my native slovene using also local slang, so do Not try any on-Line translators, you will get out a bunch of crap :-) ... but some data (measures etc.) are international, just like as photos, a lots of them :-) ... if any schematics there, remarks there are in english only to get some clue ...

... and if anyone is also interested in some other (electronics, computers, mods) stuff, can visit also (lazy-me) my a bit Outdated personal site - thats whole in english !!! ...