This is an easy to manufacture and very powerful Wi-Fi antenna like a cannon. With its help you can receive and transmit a Wi-Fi signal not only over hundreds of meters, but over several kilometers!
The antenna-gun resembles the appearance of a space blaster and, just like this fantastic weapon, has a directional and very powerful effect.
This is a directional antenna. And it is this property that gives a long reception distance due to the high concentration of the signal in one direction.
Antenna diagram
The drawing shows the dimensions between the antenna elements. Its resonant frequency is set to the middle of the Wi-Fi frequency of 2.4 GHz.
To make an antenna you will need
- Long stud with nuts.
- Metal sheet, I took copper because it is very easy to cut. In general, you can take tin from cans.
- . But you can connect to an existing router.
Making a powerful Wi-Fi gun antenna
Before you start making an antenna, you need to know that any deviation from the specified dimensions will greatly deteriorate its performance. Therefore, everything needs to be done as accurately as possible.We take a sheet of metal and roughly mark the centers of the diameters of the circles. Then we drill the center. For accuracy, before drilling, place a core or go through a thin drill, and then a thick one. As a result, the diameter of the hole should be slightly larger than the stud.
Then we take a compass and draw circles on the metal.
First cut out a square.
Then carefully cut out a circle.
The result was circles for the antenna.
I took a long hairpin. I cut off the excess along the length of the antenna, taking into account the width of the nut.
Here is the finished kit for assembly.
We assemble the antenna. Everything is very simple, like a construction set in childhood.
To control dimensions, I recommend using a metal ruler, as it is more accurate.
In the last two disks you need to make holes for connecting the cable.
We will make a connector with a cable from an old antenna from a router or adapter.
Remove the top casing.
Cut off the insulation. The antenna came off on its own because it was pressed in.
Next, unsolder the metal cap.
And the connector for connection is ready.
We tin the wheels. Copper is great in this regard. I once made such an antenna from an old computer case, so I had to tin it with acid.
We pass the cable through the hole in the last circle and solder the shielding winding to the disk.
Now we pass the middle core into the hole of the second disk and solder it.
The antenna is almost ready. I will install it on the camera bracket. There will be such a home option.
We screw it to the connector output.
You can tape it with electrical tape or tape to the bracket.
I will put the antenna on the window and point it at objects where there may be a signal.
Wow, how many networks have appeared. Although previously I only caught a signal from my router. There are not many access points in our city.
The result is amazing.
Add-ons
To enhance the effect, I decided to install such a cannon on the roof. But to do this, I need to solder a regular shielded cable, which I use for a satellite dish, instead of a connector.With the help of such a powerful Wi-Fi gun - antenna, you can transmit a signal to the garage, work, school, or country house. All materials are available to absolutely everyone, and everything is done very simply.More detailed instructions You can learn how to assemble by watching the video below. It also shows more extensive testing of this powerful Wi-Fi antenna.
PS: If you are making an outdoor version, then for insulation and against corrosion it would be a good idea to paint the entire antenna with regular metal paint.
The Wi-Fi wireless information transmission system (the abbreviation does not stand for it, it was invented as a marketing ploy) is one of the pillars of modern high-tech society. With its help, not only the Internet is distributed, but also, for example, signals from video cameras. In its physical essence, it is radio communication at a frequency of 2.4 GHz and obeys all the laws of radio wave propagation.
Therefore, if your tablet or laptop refuses to communicate with the router due to interfering walls and ceilings, you can try making a signal amplifier yourself. This is a directional antenna in the centimeter range. Its design can be pin, frame, spiral or zigzag. In this article we will try, without delving into the jungle of the theory of antenna-feeder devices, to explain to you how to make an antenna from scrap materials that will be no worse than those sold in the store.
Before you start choosing the type of antenna and putting your grandiose plans into practice, you should familiarize yourself with the fundamental laws of the theory of antenna-feeder devices. There are two of them:
- Wavelength, which determines the size of the device.
- Gain factor. The most interesting point, which makes it possible to detect a weak radio signal over long distances, is exactly why we are taking on this matter.
Tension diagram magnetic field any radio signal has the shape of a sinusoid. The distance between the first and third points where it intersects the x-axis is called the wavelength.
The frequency rating is the number of oscillations per second. Since a radio signal travels at the speed of light, the wavelength in meters will be equal to the result of its division by the frequency. For low frequency (most common) Wi-Fi range: 299792458 / 2.4 = 12.5 cm.
Remember this value, since all dimensions of the future antenna will be calculated as its fractional parts.
Gain is a conditional value that shows how many times the output signal at the terminals of a directional antenna is greater than that of an omnidirectional antenna. Moreover, this ratio is calculated as a decimal logarithm and is denoted dB - decibel. Omnidirectional is one for which the position relative to the radio signal source is indifferent. These are used in mobile phones and tablets, since this is, firstly, assumed by the terms of use, and, secondly, determined by the small size of the devices.
The directional properties of an antenna appear if its length is equal to half the wavelength. For Wi-Fi it is 6.25 cm. Its spatial radiation pattern is a torus - a donut, perpendicular to the axis antennas. The gain in this case is equal to two decibels, that is, 1.58 times. Such half-wave dipoles allow you to increase the range by ten meters, which is already good for reliable signal reception in your apartment.
The easiest way to boost a signal
If you take a ruler and measure the length of the whip antenna of a home router, it turns out that its length is from 10 to 12 cm. They don’t make it longer because in a pin whose size is larger than the wavelength, the internal resistance and the signal goes out instead of increasing. This increase in size leads to a narrowing of the thickness of the donut pattern and a slight increase in the power density of the emitted signal. Shielding the transmitting antenna on one side has a much greater effect.
The screen allows you to concentrate the radiation of the router in the direction you need. For example, if it is located against a wall, then there is no reason to transmit the Wi-Fi signal to neighbors or to the street. Its installation increases the gain of the transmitting antenna to 3 dB, that is, twice. Which actually reflects the physical essence of the matter, because you reoriented half of the uselessly directed signal in the right direction.
The trick is how far from the router antenna to place the screen. According to the laws of radio signal propagation, it should be equal to 1/8 of the wavelength. For Wi-Fi it is 1.56 cm.
It can be a sheet of iron (cut beer or tin can), a compact disc or thick foil. It is best to make the design in the form of a stand for the router, with the screen placed perpendicular to it. You can achieve the result experimentally by moving the signal source closer or further from the screen by millimeter. The network level display interface will help you.
The advantage of this method is its simplicity, and also the fact that you do not need an antenna for the tablet. That is, you don’t have to open it or look for ways to connect additional equipment. The disadvantage is the short range of signal reception.
Directional Antennas
A powerful antenna - with a gain of 10 dB - is needed if the expected reception range is at least 50 meters. In this case, highly directional antennas are used. For example, zigzag or spiral.
Zigzag
It is called both the Kharchenko antenna, after the radio amateur who proposed such a design in 1961, and the biquad antenna, for its characteristic shape. It is constructed from a conductor two waves long of the intended signal. For Wi-Fi, this value is 25 cm. It bends in the form of two squares with a side of ¼ wavelength - 3.125 cm. The point of their articulation is detachable. Usually it is attached to a dielectric plate to ensure rigidity so that there is no overlap between the soldering points of the central core of the coaxial cable to one branch and the screen to another.
The biquad antenna has a gain of 8 dB in the basic version, and about 12 dB if a screen is installed, which can be a CD, foil, or sheet of metal. The distance to it from the plane of the conductor bent into two squares is 1.56 meters - an eighth of the wavelength. The design is convenient in that the extreme points of the squares along the axis have zero potential, so they can be attached to the screen with anything, including metal wire, providing good rigidity.
To ensure the required gain, it is placed vertically. In the horizontal direction, its directional properties are no better than those of a half-wave dipole. The receiving axis is located perpendicular to the plane of the figured conductor.
Coordination with the cable is not required; it connects directly to the conductor.
The spiral antenna was invented in the late 40s of the last century by the American radio engineer J. Kraus. Very simple in design, it provides signal amplification up to 20 dB (100 times) and is used in all bands, starting from VHF. Reception range up to 2 km within line of sight. It consists of several turns of a conductor twisted into a spiral.
The diameter of the spiral turn is equal to the wavelength. Therefore, when creating the frame of a homemade antenna of this type, a section of sewer pipe is ideal plastic pipe with a diameter of 40 mm. They are in every hardware store.
The spiral is sparse. The distance between turns is ¼ wavelength. The longer it is, the sharper the radiation pattern and the higher the gain. For a distance of three kilometers, it is enough that the total length is equal to three wavelengths - 36 cm.
The conductor used is a household single-core copper wire with a cross-section of 2.5 mm 2 - diameter 1.5 mm. The insulating shell cannot be removed. It is evenly glued to the base pipe.
The screen is made of any sheet material; its position does not depend on the wavelength multiplicity.
The antenna requires coordination with the power cable. For this, a piece of copper sheet in the form of a right triangle with legs 71 and 17 mm long is used. It is glued to the pipe so that the slope of the hypotenuse follows the slope of the coil. The central core of the cable is soldered to the angle opposite the straight line (at the intersection of the hypotenuse and the short leg). The braid is soldered to the screen.
The disadvantage of the antenna is that it is somewhat bulky and somewhat difficult to position - the direction towards the router must be maintained within a few degrees.
Connection
After assembling the Wi-Fi antenna, you will definitely have a question about how to connect it. Typically, laptops and tablets do not have connectors for this. To solve the problem, buy a remote antenna for your mobile phone with a magnetic adapter that sticks to the body of the device. Disconnect the cable from the magazine device and use it for your own purposes. Of course, in this case, signal losses will increase, and the actual reception range will be slightly lower than expected. But you don’t have to open the computer and manipulate its circuitry.
A carefully assembled Wi-Fi antenna will help you get within range free networks and do not refuse Internet services even during a trip out of town.
Setting up Wi-Fi networks demonstrates quite a lot of nuances. I came across someone trying to share the Internet with home users. One computer is connected to the provider via cable. An access point mode is created, a security protocol and a password are selected. Home users use the Internet in parallel. The technique does not work, thanks to the provider using a private line. The exit is located. The obstacles that stand between people and high-speed Internet are powerless to prevent a homemade Wi-Fi antenna from improving signal reception and transmission; communication range and speed naturally increase.
Purpose of homemade Wi-Fi antennas
Antennas adorn many devices. Let's list:
- Tablet.
- IPhone.
- Laptops.
- Wi-Fi modems.
- Wi-Fi routers, access points.
- Cell towers.
A homemade antenna for a Wi-Fi adapter will expand the capabilities of electronics. The access point is distinguished by its ability to transmit the signal omnidirectionally. The power spreads, filling the azimuths. By supplementing the access point with a special external purchased, homemade antenna, it can impart directional properties to the radiation. Will increase the range of reliable reception in the selected azimuth.
Stop breaking your smartphones by connecting an external antenna and assemble it yourself for an access point. Most antennas sold in stores have a circular radiation pattern, radiating equally, omnidirectionally, dividing the power by azimuth.
Powerful homemade Wi-Fi antennas have a much smaller field of view and will provide more reliable reception in some cases. Reflector-equipped devices have a radiation pattern with one central lobe. Remove the reflector and you get a figure eight. There will be a dead zone in the plane of the emitter; there will be no signal. A homemade antenna for a Wi-Fi router is unable to receive directional signals. The access point installation scheme is as follows:
- The device is connected to a computer (electrical network).
- The channel is selected.
- The setting is carried out at full power.
- The protocol type is selected.
- The password and network name are set.
People walk around happy with the new accessible point. Let's take a closer look at the process; let's take a moment to grab a soldering iron and pliers. Like a transmitter, a radio-electronic device, an antenna, or a router have a certain peak of capabilities in the middle of the range. For example, on 2.4 GHz there are often 14 channels. The power of the transmitted signal is higher in the middle, for example, the sixth channel. Although each line occupies 22 MHz of the spectrum, the measurement is carried out at a field level of 0.707 (√2/2) maximum on both sides of the carrier frequency.
For reference. Determined by the modulation type, sometimes only the pilot signal remains, one band. Square pulses, computer signals are just like that, they have a pronounced maximum, a bunch of side lobes. As a result, the spectrum width of the real signal is infinity. The cyclic voltage band is limited, to which the process emitted by the Wi-Fi protocol does not come close.
A homemade omnidirectional Wi-Fi antenna does not best option. Nothing will change. A homemade directional Wi-Fi antenna is better; we will make it from wire, foil PCB, or copper tube. They are so sensitive. Transmitted and received powers are concentrated in a narrow sector. It will improve the quality of transmission by carefully positioning users and the access point. You can judge how important the arrangement is by one curious case:
- The office called a technician. They said: between 12.00 and 14.00 the access point collapses. The technician took out a special device for estimating occupied frequencies and began the study. Similar programs are provided by the Android OS of smartphones. Use by selecting a channel before installation. Conduct research throughout the day for several days in a row, avoiding incidents. We bring to light what the master discovered: the neighboring office, separated by a wall, painted lunch. The workers took turns using the microwave (using the 2.4 GHz frequency). Poor insulation household appliances, the lack of grounding allowed the radiation to exhibit narrow-band interference at the frequency of the magnetron. The solution to the problem turned out to be simple: the access point was moved to the opposite end of the office.
If you had a simple homemade Wi-Fi antenna from a beer can with a reflector on hand, the heroes might not know what’s next door powerful source harmful radiation. The reflector gives the access point directionality and will dampen the radiation coming from behind the wall. Another advantage of directional antennas, which we will make with our own hands today. By the way, when buying a microwave, try to determine safety. You need to plug the device into a grounded outlet, put your cell phone in the working compartment, close the door, and dial the number. The signal passes - harmful radiation from the magnetron will come out. Avoid sitting nearby. Let's discuss how to make a homemade Wi-Fi antenna.
DIY directional Wi-Fi antenna
Tools you will need:
- Soldering iron (solder, rosin, stand).
- Pliers.
- Small flathead screwdriver.
- Vernier caliper, ruler.
- Drill with a drill for a copper pipe.
Materials you will need:
- A piece of foil double-sided PCB as a reflector.
- Copper wire with a diameter of 1.2 mm and a length of 30 cm (only 26 cm of which will be needed).
- The RK-50 cable is not too long so as not to dampen the signal.
- A piece of copper tube 10 cm long for the RK-50 cable to pass inside.
Let's start with a copper tube. We saw through one end by 1.5 mm, removing two-thirds of the wall. The antenna will be soldered to the remaining piece. We create a bi-square contour with a side of 30.5 mm from wire. The size was selected based on the 2.4 GHz band setting condition.
In a similar way, you can make any antenna with a horizontal or vertical polarization signal. Including television. A homemade Wi-Fi antenna is suitable for a tablet, phone, or modem. If you know where to connect.
Please note that the side of the squares is given according to the middle section of the wire. Between the nearest edges there will be 30.5 - 1.2 = 29.3 mm. You can use it. We begin to bend, finding the middle. We use the edge of the ruler as a support and determine the state when the cut begins to balance. We make a bend of 90 degrees, this will be the point where the central core of the RK-50 will connect. We bend the wire, getting a “square eight”, both ends should return strictly symmetrically. We cut it a couple of millimeters short of the initial bend. We tin the ends and put the figure eight aside.
We mark the middle of the PCB and drill a hole so that the copper tube can barely fit in. We cheat both sides. We take a copper tube and tin the outer edge of the thin wall left by the first stage. The figure eight is 1.5 cm away from the reflector. We tin the tube in a circle, with the rim at the specified distance from the edge (without taking into account the thin wall). Solder the tube to the board, preferably at an angle of 90 degrees. We place both ends of the figure eight on a thin wall so that the initial bend does not touch the tube. We orient the figure eights parallel to the larger side of the PCB at a distance of 1.5 cm. Now the reflector is grounded.
The RK-50 cable is pulled inside, the screen is placed on the copper tube, the core is placed on the initial bend of the figure eight. We mount the connector on the opposite end, simply solder the cut to the required contacts of the modem, telephone, or any other device. Let's start the test. The figure eight must be mounted vertically for horizontal polarization. If it works, we find silicone sealant that is not afraid of frost and precipitation, and fill the place where the cable exits with the antenna with a good layer. After hardening, the antenna will successfully withstand rain.
If you replace the wire with a thick conductor PV1 of a sufficiently large cross-section (2.5 mm 2), we will strip the braid at the point of initial bending and at the ends. A homemade Wi-Fi antenna for a laptop will be protected against bad weather. Today, heat-shrinkable materials are produced. The heated film tightly wraps the product, protecting it from the vagaries of bad weather.
Manufacturing.
First of all, you need to make a reflector - this is a metal sheet 450x350 mm (the back of the antenna). It serves to reflect and transmit wifi waves to vibrators and also serves as the body of the antenna itself.
To do this, take a fairly thick sheet of iron. For example, a body from an old washing machine or a baking tray will cope with this task. We cut out the required size with a grinder and clean it from rust. see photo 1 on the right
Let's put it aside For now, put the reflector blank aside and let’s start manufacturing vibrators, which will be located on a one-sided 1.5mm fiberglass laminate. To do this, you need to purchase a vinyl vibrator stencil with a self-adhesive mounting film. Such things are made in plotter cutting workshops according to the provided drawing.
Download drawing Delta Ds 2400-21. Copy to a USB flash drive. At a plotter cutting company, explain to the manager what the actual dimensions of the drawing parts should be!
Before gluing the stencil, remove small scratches and polish the copper surface of the fiberglass laminate using a scratch pad and GOI paste. Degrease the surface with solvent (acetone)! Carefully transfer the stencil onto the copper surface of the fiberglass laminate. Let's start etching the antenna circuit board.
Pour hot water In a container of suitable size, add copper sulfate and table salt in a ratio of 1:3, mix thoroughly and lower the fiberglass down with copper. To prevent the board from sinking, first stick the foam on the opposite side using double-sided tape. Wait until the excess copper is completely dissolved. see photo 2 on the left.
When the process is finished, rinse the fiberglass with clean water and remove the vinyl from the vibrators and tracks. Make a hole for the contact of the N-235 TGT connector and tin. To protect against external environment and from oxidation, cover the side of the antenna with vibrators with insulating varnish!
Place fiberglass on the reflector, make a mark and drill a hole for the n-type connector. Also make holes for external wifi antenna mounting kit, see photo 3 on the right.
Next we need to connect the reflector and the fiberglass board together. The gap between the reflector and the vibrators should be 9mm!
Here's what we'll do - glue 6mm pieces of laminate flooring to the reflector with a THIN layer of glue. Before this, place them evenly on fiberglass using double-sided tape, see photo 4 on the left.
Laminate 6 mm + fiberglass 1.5 mm + glue 1.5 mm = gap 9 mm.
Now we install it in its place and tightly tighten the N-235 TGT connector. After the glue has dried, peel off the fiberglass (held on with double-sided tape) from the reflector. We cover the laminate and the connector with masking tape, and paint the reflector on both sides with metal paint for outdoor use. The reflector is almost ready, we attach the external antenna mounting structure.
Next, we apply a thin layer of “moment” glue to the laminate and connect the reflector with fiberglass. Having inserted the contact of the n-type connector into the hole, solder its tip to the copper track of the vibrators. See photo 5 on the right.
In this example, a protective cover for the antenna is not provided. Instead, a hybrid adhesive-sealant “Soudal Fix All Crystal” is used and applied along the perimeter between the reflector and fiberglass, See photo 6 on the left. Then the front part of the wi-fi antenna is covered with three layers of white, acrylic paint. First check the paint to see if it will shield your antenna. Paint the piece thick paper and when the paint is completely dry, close the front side of the wi-fi antenna. If the signal does not change, feel free to use this paint. See photo 7 on the right.
Let's check this product in action.
Here are the results of testing a DIY Wi-Fi antenna:
In order to connect the antenna, we need an external USB wifi adapter. This example uses "alfa awus036h 1000mw - Taiwan".
First, let's connect the adapter, without an antenna, and see what it shows us, and whether it even works? As it turned out, alfa found three points. We will focus on the connected point -66 dBm. For half an hour the signal hardly changed, and this was without any antenna. See photo 8 on the left.
Now, without changing the location, let’s check our homemade Wi-Fi antenna by pointing it towards the router. As you can see, the result is dramatically different in better side. See photo 9 on the right. The signal of the connected point has improved from -66 dBm to -45 dBm. Three more points were discovered.
66-45=21.
It turns out that the antenna gain is 21 dB.
Instructions for making a “double” Bi-Quad (double eight) W-LAN antenna - 2.4 Ghz antennas for wi-fi.
"Double Eight" is a continuation of Bi-Quad, the gain of which is 2 dB higher, i.e. is approximately 12 dB. During construction, pay attention to the fact that the copper wires do not touch at the intersection points. After construction, it is advisable to varnish the “double eight” to avoid oxidation/corrosion. The two photographs below show how important it is to maintain a distance of 15 mm between the reflector and the copper wire:
In order to avoid questions (there were in the first post), let's consider building an antenna with a circular diagram, in this case something around 270°.
First, from a copper plate (or other sheet metal/material), you need to bend a pipe with a diameter of 70 mm and a height of approx. 100 mm. Then bend a straight 6-element Quad from copper wire and, using, for example, a bottle, give it a corresponding, curved shape. I repeat for those who are not reading very carefully: the distance from the copper wire to the reflector in a circle should be 15 mm! It is important that the crossing wires do not touch each other!
Of course, this is not the only correct option for building such an antenna. The antenna with a pie chart can be made larger,
In this case, signal loss in the antenna cable will be minimized.
Ideally it should look a little different, something like this:
but this is not so important, the main thing is that you can repeat the dimensions by printing. For those bending the “double eight” - the outer squares are not used. Those who do not have a printer can use the following drawing to make a frame: the dimensions are for a wire with a diameter of 2.5 mm
"Triple Eight" is another continuation of the "double eight", the gain coefficient of the "triple eight" can be 14 dB or a little more. This is what a colored “triple eight” looks like, in general, not bad:
For beginners! Please note that the stands supporting the antenna at a distance of 15 mm from the reflector must be made of dielectric material!
The “double eight” and the antenna with a pie diagram discussed above can be mounted together in one housing:
From another.
The antenna is closed. To make the protective housing, a piece of plastic pipe with a diameter of 125 mm, which is used in plumbing, was used; the lid is made of 2 cm plastic. The top fastening nut is made of plastic. Can be painted any color.
