In fact, this device is quite simple and will not cause any difficulties in manufacturing even in an ordinary apartment. But the benefits from it will be quite noticeable, and maybe even some radio amateurs will be encouraged to take up the manufacture of such equipment seriously.
Antenna characteristics
The panel antenna consists of 2 main parts - a reflector and vibrators. The line of vibrators is connected by a common contact, from which a coaxial cable is led out, leading to the jack of the external antenna of the Wi FI router, mounted on the back of the device. The antenna works as an amplifier, which can be judged by comparing the signal power from the standard antenna of the router (the author used tp-link TL-WN722N) - 5db, and from the FA-20 - 22db.
Necessary materials:
- Foil textolite one-sided or getinaks, 430x200 mm, thickness - 1.5 mm;
- A piece of sheet metal (best galvanized), 435x205 mm, thickness 0.5-1 mm;
- TV coaxial cable RG-8X 50 Ohm;
- Drawing template of antenna vibrators printed on vinyl film;
- Photoresist;
- Ferric chloride for etching boards;
- A can of aerosol varnish for textolite;
- Soda, acetone or alcohol;
- Hardware: 3 mm bolts – 12 pcs., nuts – 32 pcs.
Tools:
- A drill with a cutting disc for cutting getinax;
- Drill with drill 3-3.5 mm;
- Soldering iron with solder;
- Painting knife, scissors;
- Pliers, metal scissors;
- Construction rubber roller for rolling films;
- Bath for etching the antenna board;
- A piece of glass and an ultraviolet lamp for photolithography;
- Hairdryer or iron to warm up the photoresist;
- Sandpaper-zero;
- Hot glue gun;
- Core, hammer;
- Metal ruler for marking holes.
Making a Wi-Fi antenna
Stage one - making a panel of vibrators
We mark a sheet of foil PCB to the size of our antenna, and cut it out with a cutting disc of a drill. This procedure can also be performed with a regular paint knife, making cuts along the marking line on both sides of the sheet, and then breaking them off by hand.
We print a template of the antenna vibrators on transparent film for inkjet printers. It will come out of two sheets, which are then easily connected to each other.
To etch using photoresist technology, it is necessary to prepare the foil side of the getinax by cleaning it with a zero. You can degrease surfaces using acetone or alcohol.
We place the photoresist film on the getinax, cutting it to size with scissors. We remove the protective layer and glue the photoresist, getting rid of air bubbles by rolling with a rubber wallpaper roller.
After this, we apply the vibrator template film and cover it with ordinary glass. We use an ultraviolet lamp to illuminate the photoresist. The holding time for different manufacturers of this material differs. The author needed 5 seconds for his film, ordered from China. for each processed area of the board.
Now it is necessary to additionally heat the photoresist so that it firmly adheres to the surface of the getinax. We remove the template, a sheet of glass, and heat the film with a hairdryer or iron through the paper. Remove the top protective layer of photoresist.
We wash off the unexposed photoresist in a baking soda solution, placing the getinax plate in the bath. After a few minutes, remove any remaining film with a used toothbrush.
Getinax is ready for pickling. We dilute ferric chloride in warm water and dip the plate into a container with the solution. It must be stirred periodically.
We saturate the old lye solution with soda ash and place the plate in it to get rid of the remaining photoresist. We wash the resulting board with plain water.
We mark the centers of the rectangles of the vibrators on the board, and use a core to drill them. The hole must be made for the mounting bolts 3 mm. The author used a step or precision conical drill, which is convenient for removing burrs.
Stage two - preparing the reflector
From a piece of galvanized sheet metal, which is the most resistant to corrosion, we cut out a copy of our vibrator plate. The holes for fastening the bolts can be easily transferred to the sheet metal by making notches with the same drill. We drill holes on the tin through a wooden lining.
We tighten the bolts with two nuts on the back side of the plate, making the required gap between the reflector 3 mm, and the total distance between the vibrators and the reflector 6 mm. We secure the tin using the third nut.
In the upper part of the reflector we make a hole for a coaxial cable, the central core of which must be soldered to the vibrator plate, and the braid to the reflector.
We solder the second end of the cable in place of the external antenna to the router. We attach it to the reflector from the back of the antenna using hot glue.
We protect the front side of the vibrator board from oxidation with aerosol colorless varnish.
For home use, this antenna can be placed on a windowsill or balcony. If you plan to use it outdoors, any bracket leading to a mast on the roof or outside the window can easily be attached to the reflector.
