Often, owners of large apartments and multi-storey private cottages want to freely use the Internet anywhere in their home. But the power of a Wi-Fi router is not always enough. An antenna can be used to improve the quality of the network. wifi router a. It is not difficult to make a structure of any power and orientation with your own hands.

By default, the factory-built router is equipped with 2dB omnidirectional antennas. It transmits the Internet in all directions at once. As a result, the signal "stretches" around the entire perimeter and weakens.

If there are one or two walls in the signal path, the impulse may not pass through them and there will be no network in the far room. The situation will be corrected by a purchased or home-made Wi-Fi antenna for a router of higher power.

An omnidirectional antenna will not really change the situation, since the signal will still go in different directions.

It is better to make an antenna for a directional Wi-Fi router. The device will concentrate the network in a narrower sector and significantly increase the signal strength.

Owners of cottages who want to use the Internet not only at home, but also on the site will need an external antenna for the router. You can buy it, but it's better to do it yourself. If it is a directional antenna, it will be able to cover a specific area with a network without distributing the Internet to the sides. It is not at all difficult to make it.

Diy directional antenna

The most popular and easy to manufacture homemade antenna for a wi-fi router from metal cans. It is easy to make, but it will not give too much signal increase.

If you need to improve the quality of the network in your home and in the surrounding area, you will need to make a more powerful device.

Components for assembly

Antenna with biquadrat

DIY biquadrat amplification

How to make a wi-fi antenna for a router:

1. take a copper tube 10-11 cm long. From one end we make a cut of 1-2 mm, removing part of the wall;
2. from a piece of wire with a cross section of 1.2 mm and 30 cm long, we will make a biquadratic contour with a working side of 3.5 cm. To do this, measure 15 cm and bend the wire 90 °. Next, we will bring the structure to a square eight and cut off the ends. They should not extend 2 mm to the middle of the wire. Let's clean it up;
3. take a piece of foil-covered PCB and make a hole in the middle. A copper tube should hardly fit into it;
4. solder the tube to the PCB at an angle of 90 °;
5. we attach a copper structure to the wall of the tube so that its middle does not come into contact with the tube and does not reach the textolite by 1 cm;
6. into the tube we will drag a piece of wire RK-50. In the middle of the figure eight we will "put" a vein. Solder the connector to the other end of the cable.

The resulting antenna to the router is mounted vertically. Your device is suitable for creating 802.11 n communication on the territory of an apartment, yard or between houses.

Other homemade devices

Any wi-fi antenna for a router with your own hands is easy to manufacture. Such a device may well replace the stock antenna by 2-3 dB, which is included in the router package and more than double the coverage area.

For outdoor use, an external 8-10 dB router antenna made of satellite dish... To do this, you should upgrade the purchased dish by placing a homemade antenna in the center and connecting it to the router. The structure is installed at the highest point of the house.

Homemade wi-fi antenna

In addition to a dish for making an antenna, you can use a homemade product made of ordinary foil. But in this case, it will need to be sheltered from rain and wind by placing it in the attic or in another closed place.

To stabilize the signal in a small room, you can make a whip antenna. This is an analogue of the stock antenna that comes with a Wi-Fi router. Such a hand-made device is much more powerful and better at distributing the network.

It requires a piece of copper wire and a BNC connector to make. Having soldered the end of the wire to the "mother" of the connector, it is necessary to twist a ring from the wire 61 mm from the base. Then after 91 mm wrap another ring and after 83 mm from the last ring cut the wire. The antenna for the wi-fi router is ready.

There are many other designs of homemade devices. Which version of the antenna for the router to choose depends only on the user, his needs and abilities. Any homemade Wi-Fi antenna for a router will help improve the signal quality at times.

Homemade outdoor omnidirectional Wi-Fi antenna

So, we need an external antenna for the 802.11b access point to which the directional antennas of all other wireless LAN (WLAN) users will be oriented. This antenna will have to receive and transmit signals in all directions, so that access to the network is available from any direction, i.e. should have a circular pattern. In other words, we need outdoor omnidirectional WiFi antenna.

Of course, there are factory solutions in this regard, but they cost a lot of money, for example, this antenna ANT24-1500 costs 175 USD (Fig. 1)

and this ANT24-0500- 65 USD (Fig. 2)

Rice. 2

And in general they make a fool of our brother and not only in this area, the cost of these products is a penny! Therefore, we will make the antenna ourselves and it will work no worse than the factory ones, since the laws of radio engineering are the same for everyone and here everything will rest only on the accuracy and quality of manufacture.
Our WiFi antenna will be a classic whip antenna with a circular pattern in the horizontal plane, called Ground Plane by radio amateurs, converted to the 2.440 MHz band we need. The antenna is a quarter-wavelength rod with counterweights of the same length at 135 ° relative to the rod.

Why 135 °? Because only with these parameters, our antenna wakes up to have a characteristic impedance of 50 ohms and wakes up to be matched with the 50 ohm cable that feeds it. This is how the characteristic impedance changes when this angle changes.

If the antenna mismatches with the cable, not all the energy suitable for the antenna will be emitted to it, that is, here it will be necessary to observe manufacturing accuracy. The length of the pin, for the middle of our 2.440 MHz band, is 27.95 mm (28 mm rounded), the length of the counterweights will be 30.72 mm (31 mm rounded).

Why is the pin shorter than the counterweights? Here we observe such a radio engineering rule as the shortening factor, since the length of the radio wave is different environments different. For our antenna, with a rod diameter of 2.28 mm, it will be equal to 0.91. It is desirable to maintain the dimensions of the pin and counterweights as accurately as possible, the characteristic impedance of the antenna also depends on this. It is necessary to try to flesh to a fraction of a millimeter, since at these frequencies the antenna is very small and even a couple of millimeters of size discrepancy greatly violates the correspondence of the length of the pin of a quarter wavelength. It is advisable to make the number of counterweights at least 12, and even better, cut a cone out of copper foil.

Practical execution

An omnidirectional WiFi antenna is made by freeing the central core of the power cable from the braid, taking into account the required length of the pin.

Counterweights are made of twisted braid of the same cable, which is retracted to the desired angle. We cut off the top cover of the cable at the level of 31 mm, remove the braid and shorten the pin to 28 mm. We tin the tip of the pin with a soldering iron so that the wiring of the central core does not disperse and remove the insulation from the central core, since if it is left, it will be necessary to recalculate the shortening factor taking into account its influence. All this must be hermetically sealed in a plastic box so that even fresh air does not penetrate.

And here is how the craftsmen do it over the hill:

Rice. eight

Firstly, only on the connector here about 2 dB is lost, we simply do not have it, secondly, the shortening factor is not taken into account, and thirdly, the shape of the connector itself distorts the shape of a theoretically correct antenna of this type.

Choice of cable.

Since the RF output of all access points usually has a resistance of 50 Ohms, we do not have much choice - the cable must be wave impedance 50 ohm. Of course, Belden's H-1000 cable with an attenuation of 0.22 dB / meter would be ideal for us, but we don't have that kind of money. Therefore, you can choose a cheaper and more affordable RK-50-7-11 with an attenuation at our frequencies of about 0.6 dB. Naturally, it should be without joints and damage, preferably new.

We connect the cable to the access point cheap and cheerful.

Usually, all connections in this matter are made using special connectors.

Rice. 12

But we do not use this for obvious reasons. Instead, we take the pliers and, without a drop of regret, we break the standard indoor antenna WiFi from the hotspot is about 2 centimeters from the bending knee of the antenna.

Carefully, there is a thin cable running inside, it will still be useful to us. Take it out along with the real antenna located inside this case.

Here she is. By the way, it is described in Fig. 4, just to reduce its resistance to 50 ohms, they shortened it to 26 mm, thereby making it less efficient than a quarter wave antenna.

We unsolder the cable at the base of the antenna pin, take it out of the tube and cut it in this place. Then we release about a centimeter of the central core from the braid, fluffing it up and bending it back. Next, we release about 4 mm of the central core from the insulation and tin this end with a soldering iron. Now we take a large cable, cut off about a centimeter of the outer sheath, move the braid back and give the inner insulation the appearance of a cone. Then, with a needle, we try to make a hole between the conductors of the core with a depth of 4 mm, preferably closer to the center of the core.

We will stick the core of a small cable into this hole.

And then, with a small drop of tin and rosin, we will mine both veins. Fill the place of the solder with molten insulation material of the central core from some unnecessary piece of the same cable. Next, we connect the braids of both cables on all sides evenly and solder so that there are no gaps, you can add copper hairs and tin for this or use copper foil. Then we wrap it all up with duct tape and get this.

For all the clumsy and sloppy product that I made, everything works at a distance of 90 m with a signal level of 61% at a full speed of 11 Mbps.

Considering that the length of my cable is about 8 meters and a friend at the other end has 12 meters of the same cable with the same connections, feeding a simple canned antenna that has not been brought to mind (who is interested - here is an article on canned Wi-Fi antenna), then I think it's very good.

After a year, I purchased a smart nokia n95 with wi-fi support and was able to make new measurements.
So, the access point is the same with a power of 15dBm, i.e. 31.6 milliwatts, the nokia n95 wi-fi module has a power of 100 milliwatts, but this is not important, since the communication range will determine the lowest-powered device in the system, i.e. at the distance where the TD hears Nokia, Nokia will no longer hear the TD due to its lower power. WiFi antennas in both cases, non-directional: on the AP everything is the same as described above, and on the Nokia its built-in antenna. According to the gps readings, I determined the distances with an accuracy of a couple of meters. After moving at a distance of 1100 meters, the connection was still stable. From the HTTP server everything rocked without interruptions, Internet access went fine, although the speed was already at a minimum of 1 megabit sec. At a distance of 1200 meters, communication was already very torn to work, it was impossible. When using more powerful APs, such as the DWL-2100AP, it will be possible to communicate over a longer distance.
There was a line of sight without any directional antennas. Although I have a suspicion that in Nokia the antenna has some directivity, although not pronounced - it catches a little better in the position with the vertical left side to the signal source. Of course, the connection will not be good in any place where the phone is turned on, usually on the bumps, the connection can be better in the lowlands.

I will show you how to assemble a very powerful antenna for receiving Wi-Fi, capable of receiving a signal at a distance of many kilometers, but at the same time lightweight and easy to assemble. Having crossed two popular antennas, a wave channel and a pouch antenna, I got the idea to create a Wi-Fi gun.

This antenna can be made from any sheet of metal. I used 0.3mm copper foil because it is easy to cut with scissors.
The parts of our antenna will be mounted on a hairpin, we need to cut 7 discs with a hole in the middle.

To do this, you need to place, punch or drill seven holes, and only then circulate the circle. If we do the opposite, then the drill can go to the side, but it is important for us that the hole is exactly in the middle.

We scratch out a circle according to the dimensions shown in the diagram and cut out our discs.

Picture 1.

You need to do it as accurately as possible, the deviation is only a millimeter and it will not work like that. The thickness of the metal and the diameter of the pin have almost no effect on the operation of our blaster and can be anything. Such circles are obtained (See Fig. 1) and after all the parts are cut out, we just need to screw them onto the hairpin, observing the size of the gaps between them.

This irradiator is easy to assemble as a constructor. We install the second plate of our
blaster at a distance as indicated in our diagram - 30 millimeters, tightening the nuts we select exactly our 30 millimeters.

On the last two discs, you need to make a hole for the wire. Our blaster is ready. Now it remains to connect it to our device. In the beginning it will be a USB modem, then we will connect it to a smartphone and finally to a router in order to distribute the Internet through our WI-FI gun.

To connect to a Wi-Fi whistle, you need to carefully disassemble the antenna so as not to damage the wire. Tinning the soldering points and soldering the wire to the outermost large disk, and the central core to the next one. We attach our gun to the bracket so that it is convenient to aim at the victim's router.

The gun catches the net even at a distance of 500 meters. Materials for a Wi-Fi gun are not expensive and are available to everyone.

The wireless system for transmitting information Wi-Fi (the abbreviation does not stand for it, it was invented as a marketing ploy) is one of the pillars of the 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 a radio communication at a frequency of 2.4 GHz and obeys all 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 to make a signal amplifier with your own hands. This is a directional centimeter-band antenna. Its design can be pin, frame, spiral or zigzag. In this article we will try on our fingers, 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 a store.

Before you start choosing the type of antenna and realizing your grandiose plans, you should get acquainted with the fundamental laws of the theory of antenna - feeder devices. There are two of them:

1. The wavelength on which the dimensions of the device depend.
2. Gain. The most interesting moment that allows you to catch a weak radio signal at long distances is exactly what we are doing this business for.

The diagram of the magnetic field strength of any radio signal has a sinusoidal shape. The distance between the first and third points of intersection of the abscissa axis is called the wavelength.

The frequency rating is the number of oscillations per second. Since the radio signal travels at the speed of light, the wavelength in meters will be equal to the result of dividing it by the frequency. For the 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.

The gain is a conventional value that shows how many times the output signal at the terminals of a directional antenna is greater than that of an omnidirectional one. Moreover, this ratio is calculated as a decimal logarithm and denoted dB - decibel. Omnidirectional is one for which the position relative to the source of the radio signal is indifferent. These are used in mobile phones and tablets, since, firstly, this is assumed by the terms of use, and, secondly, it is determined by the small size of the devices.

The directional properties of the antenna are manifested if its length is equal to half the wavelength. For Wi-Fi it is 6.25 cm. Its spatial radiation pattern is a donut torus perpendicular to the antenna axis. 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 confident signal reception in your apartment.

The easiest way to amplify a signal

If you take a ruler and measure the length of the whip antenna home router, it turns out that its length is from 10 to 12 cm. They do not make it longer because in the pin, the size of which is larger than the wavelength, the internal resistance significantly increases and the signal is extinguished instead of amplification. This increase in size leads to a narrowing of the thickness of the "donut" of the radiation pattern and a slight increase in the specific power of the emitted signal. A much greater effect is obtained by shielding the transmitting antenna on one side.

The screen allows you to concentrate the radiation of the router in the direction you need. For example, if he is standing against a wall, then there is no reason to transmit a Wi-Fi signal to neighbors or to the street. Its installation increases the gain of the transmitting antenna up to 3 dB, that is, two times. 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 antenna of the router to place the screen. According to the laws of propagation of radio signals, it should be equal to 1/8 of the wavelength. For Wi-Fi, this is 1.56 cm.

It can be a sheet of iron (a cut beer or tin can), a CD, or thick foil. It is best to make a design in the form of a stand for the router, perpendicular to which the screen is placed. You can achieve the result empirically by moving the signal source closer or further from the screen by millimeter. The interface for displaying the network level 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 opportunities to connect additional equipment. The disadvantage is the short range of signal reception.

Directional antennas

A powerful antenna with a gain of 10 dB or more will be 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 also called the Kharchenko antenna, after the name of the radio amateur who proposed such a design in 1961, and biquadratic - for its characteristic shape. It is built from a conductor with a length of two waves 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 of the wavelength - 3.125 cm. The point of their articulation is separable. Usually it is attached to a dielectric plate, to ensure rigidity, so that there is no closing of the soldering points of the central core of the coaxial cable to one branch and the screen to the other.

Antenna biquadrat has a gain equal to 8 dB in the basic version, and about 12 dB if a screen is installed, which can be a CD, foil, 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 provide the required gain, it is placed vertically. In the horizontal direction, its directional properties are no better than that of a half-wave dipole. The receiving axis is located perpendicular to the plane of the figured conductor.

No cable matching is required, it connects directly to the conductor.

The spiral antenna was invented at the end of the 40s of the last century by the American radio engineer J. Kraus. Very simple in design, it provides a signal amplification of up to 20 dB (100 times) and is used in all ranges, from VHF. Reception range up to 2 km within line of sight. It consists of several turns of a conductor twisted in a spiral.

The diameter of the coil is equal to the wavelength. Therefore, when creating a frame for a homemade antenna of this type, a piece of sewer plastic pipe with a diameter of 40 mm is great. You can find them in every hardware store.

The spiral is sparse. The distance between the turns is ¼ wavelength. The longer it is, the sharper the directional 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.

A household single-core copper wire with a cross section of 2.5 mm 2 - diameter 1.5 mm is used as a conductor. The insulating shell is not removable. It adheres evenly to the base pipe.

The screen is made of any sheet material, its position does not depend on the wavelength multiplicity.

The antenna needs to be matched with the power cable. For this, a piece of copper sheet is used in the form of a right-angled triangle with legs 71 and 17 mm long. It is glued to the pipe so that the slope of the hypotenuse repeats the slope of the coil. The central core of the cable is soldered to the corner opposite the straight one (at the intersection of the hypotenuse and short leg). The braid is soldered to the shield.

The disadvantage of the antenna is some cumbersomeness and a certain difficulty in its positioning - the direction to the router must be maintained with an accuracy of several degrees.

Connection

After assembling the antenna for Wi-Fi, you will definitely have a question about how to connect it. Usually, on the cases of laptops and tablets, connectors are not made for this. To solve the problem, buy an external antenna for mobile phone with a magnetic adapter that sticks to the body of the device. Disconnect the cable from the store device and use it for your own purposes. Of course, in this case, signal losses will increase, and the real reception range will be slightly lower than the expected one. But you don't have to open the computer and manipulate its circuitry.

Neatly assembled Wifi antenna will help you get in range free networks and do not give up Internet services even during a country trip.

Wireless Wi-Fi technologies are ubiquitous today. This radio standard provides for the transmission of a signal on the 2.4 GHz frequency. For practical purposes, it is used to switch the interactive connection between the access point and the subscriber's device. The quality of the transmitted signal directly depends on the built-in or external repeater. You can expand the capabilities of the router if you know how a do-it-yourself wi-fi antenna is made. Next, we will consider several methods and step-by-step instructions for them.

Amplifier from CD packaging

It is quite simple to make it from scrap materials, subject to the main rule: the distance from copper elements to the reflective surface of the disc must be strictly 15 millimeters.

The procedure consists of several stages:

1. The usual plastic packaging for 25 discs is taken.
2. The fixing protrusion must be cut at a distance of 16-18 mm.
3. With the help of a file on a plastic spindle, slotted sockets are made to fix a double rhombus.
4. The biquadrat (rhombus) is made of copper wire with a diameter of 2.5 millimeters.
5. At this stage, you need to be careful, because it is the most important. Take 300 mm of copper cable, protect the surface, bend a rhombus from the wire. The distance between the centers is strictly observed within 30 mm. If the whole procedure is carried out correctly, the result will be a double geometric figure.
6. Then the ends of the wire are sealed, and a place for attaching the coaxial cable is prepared.

Antenna for a Wi-Fi router: assembly and verification

At the next stage, you will need to attach the resulting biquadrat to the spindle, observing a vertical distance of 16 mm at all points. Using a soldering iron, the ends of the wire are fixed. Using silicone glue, attach a standard CD to the bottom of the box. Using the same adhesive, a double rhombus is fixed on the spindle.

Then the do-it-yourself wi-fi antenna is connected to the router (router). The photo below shows a diagram of how to do this. Experienced craftsmen can unsolder the standard antenna and attach a new amplifier, however, you need to be very careful here, since thin conductors can come off the board under the influence of high temperature. An easier way is to install a new device using. The result obtained, despite the simplicity of the process, will pleasantly delight you.

Tin can amplifier

Such a do-it-yourself wi-fi antenna is no more difficult to manufacture than the previous version. The device will enhance the signal, which in the apartment is weakened by partitions and furniture. The design in question is simple and cheap.

To manufacture the device, the following elements are required:

• wardrobe trempel;
• a couple of liter cans of beer or soft drinks;
• ordinary soldering iron and solder;
• wire (50 Ohm);
• connector connector.

The trempel can be replaced with a metal-plastic tube, which is used both indoors and outdoors, since it is not exposed to atmospheric influences.

Step-by-step instruction

In the future, the amplifier for the antenna is made in compliance with the following steps:

1. Holes are made in the bottom of the cans, after which they are put on the lower part of the trempel or pipe.
2. The slots in the cans are made in such a way as to avoid excessive tension or slipping of the part. The pipe is looped back and fitted with a suitable clamp.
3. A similar antenna for a Wi-Fi router, located on a trempel, requires stripping the soldering point, after which the ends of the wire are soldered to the banks one at a time. The other end of the cable is secured to the connector used to connect to the access point.
4. If a metal-plastic pipe is used as a base, both cans are soldered to the main wire. An adapter can be fitted between them and the feeder can be fixed on one of the cans. The antenna shield will be a metal foil in the tube cavity. In order to solder the braid to the foil, it is necessary to carefully make an incision and remove protective film... The attachment point should be fixed and insulated.

sheet metal

For the manufacture of this structure, a sheet of 222 by 490 millimeters is required. It must be bent in the form of a trough. Then, eight holes are made around the perimeter with a core at the same distance. At the edges they should be 8 * 2 in diameter, and in the middle 8 * 8 mm. These jacks will serve as the places for the vibrators. These elements are easiest to make from tinned food tin, and then solder them into the prepared sockets.

An antenna amplifier made of tin requires maximum precision while maintaining dimensions. Do not forget to make holes for the posts as well. Their diameter depends on the thickness and characteristics of the material used as the holder. On the side of the vibrators, it is advisable to fill the connecting joints with varnish or wax to avoid moisture ingress. Any connector can be used for connection (BNC, N, F). The last element easiest to insulate. With a router, a homemade Wi-Fi antenna is connected with the second end of the wire to the corresponding connector.

During installation, it is desirable to achieve a direct line of sight of the transmitting and receiving amplifier. It should be borne in mind that deciduous trees jam the signal. The connecting cable should be as short as possible. If you can't do this, don't use PCI cards.

Typically, it will be sufficient to use a regular white cable with dense insulation (RG-6U), since more expensive options have the same effect. With a lot of air pollution and saturation of the WI-FI zone, it is permissible to change the polarization of the amplifier if the connection is made between two identical points. Above, several ways were considered, how to make a Wi-Fi antenna with your own hands? Consumer reviews indicate that similar device has almost the same effect as a factory device, while its cost is an order of magnitude lower.