DIY Kharchenko antenna for 3g modem. street options

Today, many citizens use wireless Internet, but at the same time they strive to increase its speed. After all, excellent access is guaranteed when the modem is located close to the base station of the mobile operator. In this regard, those who work on the Internet far from the station are content with low speed. Is there a technical way to solve this problem? The best option is a DIY 4G antenna.

Panel 4G antenna

To make the panel you need to prepare the following parts:

• sheets of galvanized iron measuring 33.4 x 29 cm (for the panel) and 11.8 x 7.05 cm (for 4 patches);
• copper wire with a diameter of 2 mm;
• a circle of copper foil with a diameter of 21 mm;
• 4 pieces of thin foam according to the size of the patches;
• glue for attaching patches to foam.

Patches are arranged in 2 rows of 2 pieces. 2 pieces of copper wire are soldered to them crosswise. A hole is drilled in the panel through which the antenna cable is threaded and soldered to the wire. The patches and the panel are connected to each other through the foam using glue.

The procedure for manufacturing a 4G panel antenna according to Soviet drawings under the code F-20 is presented in the video below. The following materials will be required:

• rectangle of foil PCB 43 x 20 cm;
• 8 M3 bolts and 32 nuts for them;
• transparent printing film for inkjet printers;
• photoresist film;
• reagents - soda ash and ferric chloride.

The antenna vibrator pattern is printed on printer film. The textolite is cleaned and degreased. A photoresist film is glued to it using a roller, onto which the template is applied. The photoresist is illuminated with an ultraviolet lamp for 5 seconds (the time is indicated in the manufacturer's instructions for the film).

The exposed areas are frozen, and the areas of the film where the light does not reach according to the shape of the template are washed. The surface is heated with a hairdryer and immersed in a solution of soda ash, in which, after 2-3 minutes, the unexposed photoresist is washed off with a brush. The board is then etched with a ferric chloride solution for 35 minutes and again immersed in an alkaline solution for 1.5 hours in order to wash off the unexposed photoresist film. After this, the vibrator is ready; it is washed with warm water.

In each of the 8 segments of the vibrator, holes with a diameter of 3 mm are drilled in the center. A reflector of the same size as the panel (43x20 cm) is cut out of a tin sheet. The sheet is combined with textolite. Using a drill with a diameter of 3 mm, holes are made in the same places as the vibrator. M3 bolts are inserted into the holes of the textolite board; on the other side of the panel, 2 nuts are screwed onto each bolt. Two nuts and the thickness of the textolite give the desired 6 mm between the vibrator and the reflector. The tin sheet is tightened with nuts.

A cable is soldered to the resulting antenna and connected to the Wi-Fi router via a USB port. The central core is attached to the vibrator, and the braid is attached to the reflector. The router board is connected using hot glue to the back of the reflector. The vibrator is coated with a special non-conductive varnish to prevent copper oxidation.

Emitter manufacturing

The radiator for the biquad antenna will be a section of the central core of the coaxial cable. It must be stripped so that the length is 10-20 mm, while the shielding layer must also be preserved. This can be done by removing the top layer of insulation, cutting and folding the outer braid and foil back. The second insulating layer will be exposed, which is removed directly to the required dimensions.

Communication range

The following factors influence the radio range:

1. Location of BS and MS and terrain.
2. MS power and sensitivity.
3. Power and sensitivity BS.
4. Antennas used on MS and BS.
5. The will of the Lord God (experienced signalmen joke that this is the main thing).

Typically base stations have a power of 20 - 30 W. Antennas are used either whip or directional. The sensitivity of base stations is -100 dB - 115 dB. The user, of course, cannot change or influence all these parameters. The output power of the phone is 0.3 - 2 W, sensitivity - 90 - 105 dB. The sensitivity of a phone is mainly determined by the technologies used to create low noise input devices. If in areas of reliable reception the difference in sensitivity and power between models is almost unnoticeable, then in an area of ​​​​uncertain reception it can become critical. Often the handset shows the signal level from the base station as 1 - 2 cubes (on the scale), but cannot establish a connection: there is not enough power. And although the ETSI standard regulates the standard output powers for each class of phone, the actual value may vary slightly. Tubes from SAGEM, Alcatel, and Motorola have good sensitivity. And all old phones pass in terms of power, especially Motorola. All phase 2 phones have approximately the same power.

As for the terrain, waves travel better on flat terrain and along the river. The higher you are (within reason), the better the signal. The forest sometimes dampens the waves more than urban buildings.

DIY Kharchenko antenna for 4g modem

The device is named after the engineer who first came up with it. This powerful external antenna for a 4g usb modem is made by hand; the diagram for the desired option can be found on the Internet. We will give the simplest one.

You will need copper wire and a 2mm thick aluminum sheet. First you need to bend the wire so that its sides do not touch in the middle. And solder the ends.

A hole for the cable is drilled in the center of the plate.

Then the wire is attached to the platinum. It should not touch the reflector.

Distance 3.6 cm.

Next, it is attached to the satellite dish bracket or simply to a stick.

If the modem has a connector for an amplifier, then all that remains is to connect it. If not, then you also need to prepare it yourself. Need copper foil for printed circuit boards. Wrap the modem 2/3 of the way around. Solder the cable. Make a second layer. And secure it.

All is ready!

You can also read the review of 4g Mimo antennas and find out how to set up 4g on your phone.

How to test changes

You can just “surf” the Internet a little to determine whether the speed has improved or not. If you need accurate data, measure your speed using any service, for example, SpeedTest or Yandex.Internetometer. This must be done before and after installing the antenna on the modem.

We go to the website and start the procedure. Evaluate the result when the process is completed. Repeat it several times and calculate the average value - the indicator will be the real speed.

Click on "Measure" on the website

If you need a simple antenna that does not require special skills or knowledge to make, make a wire or can antenna. You can also take the option with a colander or an old satellite dish. For more experienced people, more complex methods are suitable - the Kharchenko antenna or the “Double Ring”.

Antenna for the Internet at the dacha

The most common Internet option in rural areas is mobile. To increase the signal level and distinguish it from interference, owners of summer cottages use various types of antennas that allow them to establish uninterrupted radio communications. 3G and 4G coverage areas are available almost everywhere, but there may be problems with stable radio communication due to obstacles that degrade the signal.

The operating principle of all radio signal amplifiers is the same, but the design and technical characteristics differ from each other. Externally and in their use, they do not differ from ordinary television ones, they are only divided according to the power of receiving radio waves. The main characteristic of the antenna is the operating frequency. You need to find out which signal is the strongest in a particular place in order to determine the range of the radio antenna for the Internet in the country. A weak 4G signal can be preferred to a stable 3G.

Note! An external antenna for a computer for the Internet must be mechanically strong, resist wind, and be resistant to high humidity and temperature changes. To strengthen a weak signal, use a radio antenna that is pointed at the nearest base station

The higher it is raised above the ground, the faster the signal will be received. It is securely fixed in a position where signal reception is best, and it is easily accessible so that it can be corrected

To strengthen a weak signal, use a radio antenna that is pointed at the nearest base station. The higher it is raised above the ground, the faster the signal will be received. It is securely fixed in a position where signal reception is best, and it is easily accessible so that it can be corrected.

Moving the signal amplifier outside the building eliminates attenuation and reflections that are created by various parts of the house:

• a powerful 3G/4G signal from a cellular operator’s base station is picked up by a radio antenna, which is located on the facade or roof of the house;
• the signal is transmitted via cable to the modem, which is inserted into the router;
• The router distributes the Internet via a LAN cable, Wi-Fi to the N number of subscribers.

What is the Kharchenko antenna and how does it work

The so-called Kharchenko antenna, which is intended for a 3G modem, is a homemade model. There is nothing particularly complicated about its design. The zigzag design was proposed by scientist K. Kharchenko back in the 1960s. Today it is quite popular among radio amateurs not only due to its simple design, but also excellent repeatability and broadband. This last advantage applies particularly well to the spiral design.

In terms of their design, models can differ quite significantly. Based on the size of the plate, the frequency of the structure changes significantly. At the same time, you need to take into account that homemade antennas may include objects made of plastic and metal.

The antenna for the modem comes in different types. The simplest one is omnidirectional. It can receive and transmit signals in all directions equally intensively. In particular, this could be a simple quarter-wave vibrator. To put it simply, this is a piece of wire that has a length of a quarter of the wave of the signal that is being received.

A sector antenna can limit radiation in a specific sector. In particular, if you place an iron sheet behind the omnidirectional device, you get a sector design. Its sector will be 180 degrees. Such an iron sheet is called a screen.

The most effective is a directional design. Thanks to the correct choice of screen curvature, you can create a narrow beam that will emit a radio wave.

The main antenna units are:

• a vibrator that induces, induces, a wave of electromagnetic oscillations that are sent by the cellular operator’s transmitter;
• a cable together with a matching unit that transmits the induced signal directly from the vibrator;
• signal transmission unit from the cable directly to the modem input;
• a reflector that eliminates interference as well as reflected signals to increase receiving power.

The DIY Kharchenko antenna is an excellent device for anyone who wants to have high-quality communications without having to spend large sums of money. It is very easy to make even for an ordinary person who does not have the appropriate professional skills. The result is truly excellent. This design will last for a long time.

Device and optimal dimensions

As you know, the 4G modem operates at a frequency of 2100 MHz. It is equivalent to a wavelength of 143 millimeters. Nowadays there are still models that are created at 900 MHz, and those that use a composite order, but they are already losing their relevance.

The key components of the amplifier are:

• vibrator - waves of magnetoelectric oscillations are induced on it, which are sent by the 4G provider’s transmitter;
• antenna wire with a matching element that transmits the induced radio signal from the vibrator;
• block for transmitting a signal from the wire to the modem input;
• a reflector that eliminates signal interruptions and reflective noise - it is needed to increase reception power.

Basic requirements for a vibrator

It is important to pay attention to the type of metal used. As a rule, copper or aluminum is used for the amplifier. In home situations, taking into account the small parameters of the vibrator, it is easier to connect the cable by soldering. For this reason, you should immediately focus on copper, without even evaluating a number of its other positive aspects.

A special role is played by the configuration and cross-sectional dimensions. It is recommended to construct a Kharchenko antenna from a wire with a cross-section of at least 5 mm² and a diameter of 2.5 mm, since these parameters, according to popular experience, are the most favorable. It’s worth mentioning right away that it is permissible to take a thickness of 2.3 mm with a cross-section of 4 mm², which will not significantly reduce the reception characteristics. If necessary, it is permissible to install with a cross-section of 2.5 mm², but this will already spoil the quality of the signal and increase its attenuation. Although for any specific case or area this may be quite possible, it should be approached individually.

To receive a reliable signal, you need to pay attention to the symmetry of the squares and the equal size of the side surfaces.

Cable selection

The main difference from standard antennas that a private master may encounter is the size of the wave resistance, and it can be 75 or 50 Ohms. To reduce power losses, it is more reliable to use a wire with lower resistance. It is more suitable in terms of electronic performance, is more consistent, and guarantees the least signal loss. However, when using one of these types of wires, it is better to more accurately select the mechanical dimensions of the vibrator for it. In this case, signal power leaks will be minimal.

Specifics of the reflector design

Any steel plate can serve as a screen. It can be cut out of tin or cut out with a grinder from an unnecessary aluminum pan. If there is no metal, then you can get out of the situation and take plywood or cardboard and cover it with foil. You don’t have to worry about the result—there won’t be a noticeable difference. In any case, the resulting structure will be able to block the moving wave background from different sides.

A used DVD disc performs well. You can increase its effectiveness by covering one side with aluminum foil. This option does an excellent job of reflecting waves. Its additional advantage is its aesthetic appearance and significant ease of work.

To use the disc, you just need to coat it with glue and fix it on the cap of a plastic bottle. You also need to adjust the distance of the vibrator from the reflector. This can be done using additional washers (you can take them from screws) or trimming excess thickness.

When assembling an amplifier, you need to pay attention to the parallelism of the areas of the vibrator and reflector.

Application of panel antennas for operation in 4G networks

An outdoor LTE panel antenna is most often used to improve the quality of data exchange in areas with poor reception.

Small dimensions and high technology make it possible to place a large number of elements in one housing, which is especially important when using MIMO technology

MIMO technology

MIMO technology allows you to increase the throughput of a data transmission channel to the maximum theoretically permissible value. This technique produces spatial encoding of the signal due to the fact that reception and transmission are carried out by different antennas. The main requirement for successful use of MIMO technology is that the coupling between antennas should be as weak as possible. Technical language says that the antennas should be weakly correlated.

MIMO antenna

Equipment that supports MIMO divides the signal into several streams, distributing them among users. If there are fewer users than the number of transceiver modules, then each client can receive a signal through several streams.

So the following happens:

• Data transfer speed increases;
• Noise immunity is increasing;
• Traffic interception becomes more difficult.

MIMO technology requires both provider and customer equipment to support it.

Simple external 4g antenna with your own hands

When thinking about how to make an antenna yourself, you need to evaluate what raw materials are available in the house. If a consumer of Internet services has a case from a computer that has fallen into disrepair at home or in the country, you can use it as the basis for an antenna. You will need to purchase a USB cord for a signal amplifier and scissors for cutting iron from the store.

You will need to cut out a structure from the back wall of the case, which is based on a rectangle 24 (width) by 20 cm, from which a thin long part 7 (width) by 14 cm extends down. In this “leg” a square hole is made for the cable (2 by 2 cm), as well as holes for a thin metal bending structure (the dimensions of the latter are 23 cm long by 2 wide), cut from the same body, and for a locking bolt. The scheme for cutting the body into components is very simple; the corresponding marks can be made with a pencil.

Description of a homemade receiver

With appropriate settings, this antenna is both an amplifier and a receiver. The inventor and scientist Kharchenko suggested using this biquadrat as an antenna. Biquadrat is a subspecies of loop antennas, which are primarily classified as zigzag.

K. P. Kharchenko proposed this device as an antenna in the middle of the last century (1961) for use as a television receiver. There is a good reason for this: it is a historical, recorded fact that, having tuned his antenna to a frequency of 14 megahertz and giving it the required position, the scientist received a signal from America.

Among the factory models of amplifier antennas, it is easy to find powerful devices with high performance. But quite often you can get by with a simple design that can be easily assembled from available materials with your own hands. It is enough to use the well-known development of Kharchenko.

According to the creator’s research, in terms of output parameters, the antenna reliably enhances the operation of digital devices operating on mobile platforms, generating an increase in signal reception of up to 3-4 dB, even without the use of a reflector, and with its implementation - up to 8-9.

The first option is directional devices

When there is a signal on the 3G modem, but it is not strong enough, then you can get by with quite simple devices in order to achieve better quality of mobile Internet reception.

Typically, this measure consists of better positioning the modem and pointing its standard antenna in the desired direction (towards the tower). An ordinary tin can, an old pan, dishes, or even a simple disc may be suitable for these purposes.

For example, if we talk about a can antenna, then you only need to punch a hole at the base or in the bottom in which the modem itself would be securely attached. In fact, the signal should be significantly stronger if you choose the right direction.

An example of a homemade can antenna

Those who use old disks to amplify the signal do it even simpler. The main thing is that they are opaque. But you shouldn’t expect great achievements from this method.

If you need to make the signal a little better

No special engineering skills are required if you adapt old dishes to enhance signal reception. Colanders or saucepans with handles work especially well. Then you can attach a USB cable to the handle, and move the modem itself a little into the inside of the dish, something like this:

Another simple way to improve signal reception with a 3G modem

Reasons for poor internet on your phone

If a user on his phone encounters problems with Internet speed, then this may be a consequence of certain factors. Some of them depend on the location.

If the connection speed is weak, then the reasons for this may be the following:

• Exceeding the permissible mobile traffic limit, as a result of which the speed will be reduced until the end of the day or month by the operator, depending on the tariff.
• Weak cellular network signal, as a result of which it does not pick up the 4G/3G network. Currently, the 3G coverage of mobile operators is quite good, in contrast to the 4G standard, which is still being introduced.
• Uneven terrain in which the subscriber is located. Hills, mountains, ravines and forests, as well as all kinds of concrete obstacles, greatly reduce the quality of the transmitted signal.
• Any operational errors, viruses or glitches.
• Long range to the tower.

Important! An Internet antenna for your phone can help strengthen a poor signal if it is caused by long distances and uneven terrain.

Cutting files with administrator rights

To say goodbye to unnecessary information, you can also use administrator rights. For this:

• First, enter cmd into the search bar of the Start button.
• Secondly, right-click on the result obtained and select the line “Run as administrator”.
• Thirdly, in the window that appears, enter the command oppwiz.cpl and press the “Enter” button.
• After these steps, the “Uninstall or change a program” window will open, where you can find the desired program. And delete it by clicking the appropriate button.

Protection

To protect from external influences, the remote antenna must be placed in a housing of suitable dimensions. The exit points of the cable and fasteners must be carefully sealed.

Important! The body of the structure must be made of non-conductive material. It can be polystyrene or polyethylene

The first material is preferable because it allows the body to be assembled by gluing and is sufficiently resistant to ultraviolet rays, low and high temperatures.

External devices are at their greatest risk during a thunderstorm. A lightning strike that hits an antenna can instantly damage the internal circuits of all equipment connected to it. Therefore, if there is a possibility of a thunderstorm, you should disconnect the antenna cable from the modem or router connector.

Homemade devices for increasing the received signal power can improve the quality of reception, the speed of reception and data transmission, eliminating additional costs for more advanced equipment.

Characteristics of external amplifiers for the modem

The main parameters characterizing the operation of an external antenna should be considered susceptibility, which determines the quality of the captured signal, and gain, which describes the signal redirected by the device. Both of these quantities are supposed to be measured in dBi.

Important! The characteristic that describes how sensitive an antenna is is a negative value (as opposed to gain). What unites these quantities is that the large value of the modulus of the number is highly valued

For example, a sensitivity of -85 dBi would be preferable to -70. In turn, a coefficient of 10 dBi is valued higher than 5.

Settings

The setup method is similar to how a satellite dish is installed on a television satellite. On the Internet it's a little different. The plate must be directed lower. You may even have to point it down. This is due to the curvature of the reflection. To set up a satellite dish as efficiently as possible, you need to rotate it and use a special program to monitor how the Internet connection changes. Once you are sure that you have obtained the maximum value, the antenna must be fixed.

The external 4G antenna is fixed, now we can move on to the next step. Now it's worth experimenting with focus. For different modem models it is necessary to configure the converter holder differently. To do this, you need to change the focus position and monitor the quality of signal reception.

In order to correctly adjust the focus, you need to know that the modem antenna is on the opposite side from the USB. Of course, this is not the case on all models, so it’s worth disassembling it to understand where the receiver is.

If you have not achieved line of sight conditions, then you should raise the structure. Increasing the diameter of the mirror can also help improve signal quality. A 4G directional antenna is capable of picking up signals over a long distance. How is diameter related to reception quality? On average, a dish with a diameter of 1 m provides a fairly good Internet connection at a distance of 30 km from the station. To connect the modem to your computer, you need to buy a USB cable. What should it be like? Of course, you should use a high-quality cord, a small cross-section with shielding and ferite at the ends. You can also purchase several of these cords and connect them together, without losing quality.

It should be remembered that you will not be able to use a satellite dish for television and strengthen your Internet connection. Of course, you can attach the modem to a satellite dish to boost the signal a little. But it should be remembered that if the dish is tuned to TV, you do not need to turn it away from the satellite. A high-quality signal can be obtained if the satellite dish is configured for line-of-sight conditions.

Tips and safety precautions

Homemade gun antenna for the Internet: diagrams and drawings

When making such precision equipment as a microwave antenna, it is recommended to take note of a few tips:

1. Tip 1. When working with copper wire, when creating bends, you need to operate not with the external, but with the internal value of the length of the biquadrate edge described in this article - Lin = 30.5 - 3.6 = 26.9 (mm). With a tolerance of 0.5 mm, this value can be rounded to 27 mm. Also, to ensure verification, it is better to create a template drawing, for example, for a device, on a real scale, drawn with lines 1.8 mm thick, and then, by applying the future antenna to it, check the manufacturing accuracy.
2. Tip 2. If the wire initially has small bends (waves), do not try to straighten it with pliers, this will not lead to the desired result. Instead, you need to find a wooden block and fix it on the table (clamp, screws, etc.). Put on fabric gloves and, stepping back from the edge of the wire 30 - 40 cm, firmly grasp it. The end must be taken with pliers, then from the beginning to the gripping point, bending the wire over the edge of the beam, pull it several times with force (in one direction). With this method, all minor irregularities will be completely eliminated. If the length of the leveled area is not enough, you need to repeat the procedure from the end of the leveled area and above, but placing pieces of hardboard between the jaws of the pliers so as not to scratch the copper.
3. Tip 3. In the case when galvanized steel is used, soldering of elements must be done using soldering acid. If aluminum was chosen as the material, connections are made using rivets or threads (bolts and nuts), soldering this metal at home without specialized equipment is impossible.
4. Safety precautions when carrying out installation and soldering work. The first thing to remember is that when working with metals you need to use safety glasses. If you plan to use machines with rotating elements (emery wheel), the use of gloves is strictly prohibited. Sleeves should be no longer than elbow length, and hair should be tied back with an elastic band or beret. The second important rule is compliance with standards when performing soldering. The room where work is carried out must be well ventilated. The use of safety glasses is mandatory. When rosin, flux or acid is exposed to high temperatures, vapors are formed that can enter the lungs, so it is advisable to use a tight-fitting respirator with carbon filters.

Types of external antennas by design

In this case, there are several possible options:

• Parabolic;
• Pin;
• Sector antennas for 4G Internet;
• Circular omnidirectional;
• With wave channel;
• Panel.

Note! Each external antenna for a 4G modem has its own characteristics

Directional antennas (“Wave Channel”)

A characteristic feature of such products is a narrow radiation pattern. The main purpose is to receive and transmit signals while maintaining one direction. Depending on the installation, the effectiveness of two important parameters is determined:

• Radiation;
• Reception of radio waves.

This type requires additional adjustment of special precision

It is important to ensure that you point to the desired station. Only in this case will the device be as effective as possible.

This is how any antennas work to boost 4G, LTE, 3G signals.

Note! Often such structures are also called beam structures. Other names:

Other names:

• Yagi-Uda;
• Christmas tree;
• Wave channel. Another name is the MIMO antenna for a 4G modem with amplification.

Panel antennas

Such devices are among the most common for receiving and transmitting radio signals. A variety of directional models. But the radiation pattern of the panel ones is larger when compared with the previous type. Thanks to this, the process of setting up basic parameters is simplified. It is enough to correctly turn the device towards the base stations to get the optimal result from using the antenna to boost the 4G signal.

The products have three important advantages:

• Broadband;
• Versatility;
• Supports all popular signal transmission formats.

The kit consists of an antenna array, which itself is essentially dipoles located one below the other in two columns. Horizontal spacing is the name given to the method of arranging parts of the structure in this case. In the direction to the base station, the signal quality is constantly improving with this organization. Dipoles can be positioned differently, depending on the polarization:

• X-shaped in both columns;
• Horizontally, with an inclination of 45 degrees;
• Vertical.

Note! The 4G amplifier antenna frames are often combined into a single housing that looks like a flat panel. For this installation, the design received the name

Circular omnidirectional antennas

Suitable for use in conjunction with all current standards for data transmission and voice messages. Any modern technologies are supported:

• LTE 2600;
• UMTS-2100;
• LTE 1800;
• GSM-1800;
• GSM-900.

In this case, you can refuse precise installation in the direction of one or another base station. This is the omnidirectional variety. But their gain remains quite low. Only in some cases will it allow you to increase the signal level from uncertain to stable for a 4G LTE antenna for a USB modem.

Whip antennas

A variety of circular omnidirectional products. An asymmetrical vibration system is the basis for these devices. It is made as a rigid rod made of metal. The round shape has become a distinctive feature for the radiation and reception patterns. When organizing communications between mobile objects, this design option is very convenient. The signal comes from all directions, no fine tuning is required.

Sector antennas

Note! They are used when a base station is deployed, which is characterized by a large subscriber base. Products are designed specifically for operator towers using sector organization

The basis is a phased array circuit, with the formation of a 60-degree sector.

One of the main features of the design remains DC closure. Therefore, sector options are allowed to be used even where particularly difficult climatic conditions exist. The need for additional means for water protection then disappears. Directional 4G antennas cannot boast of such advantages.

Parabolic antennas

A relevant option if the operator’s tower is located far enough - at a distance of up to 20 kilometers or more. The solution has not become widespread due to difficulties encountered with installation and settings.

Note! Powerful parabolic 4G antennas are offset and direct-focus in design

Other homemade antenna options

Ideas for homemade antennas could be the following:

1. Colander 4G. Everyone has a simple aluminum colander in their home. You need to fix the USB extension cord on the handle of the cookware. Connect a modem to it - it should ultimately be within the circle of the bowl. We direct the colander to the base station and catch the signal.
2. 3G/4G satellite dish. If you have an old satellite dish, use it. The signal will be amplified significantly, since the antenna will be outdoor. Remove the converter from the boom. Secure the modem at this location. Naturally, you will need a USB extension cable - carefully stretch it to the modem and connect it. Now point the dish at the operator tower. To adjust, you will need to rotate the plate slowly to achieve maximum effect.
3. Antenna "Double Ring". The method is similar to the Kharchenko antenna. It is just as effective, but here you also have to work hard to make the antenna.

Making an antenna from a tin can

The advantage of this homemade antenna is its accessibility. You can find a loose tin can in every home, be it for coffee or carbonated drinks. It is better if it is cylindrical - without corners. The jar will be a kind of “hearing aid” for the waves. They will reach the bottom and be reflected from it. As a result, a standing wave will form in the bank.

What needs to be done with the can to make an antenna from it:

1. Let's consider the simplest option - without using wires. All you need is a bank and a modem. Remove the lid from the jar. We make a hole in the wall closer to the bottom so that the modem can fit into it.
2. We place the modem in the hole so that the back part with the built-in antenna is in the can.
3. We take a USB extension cable and connect the modem to the computer through it. We place the modem with the can on the windowsill or closer to the window. We look at the number of divisions and adjust the position of the can with the modem to maximize the signal.

   Insert the modem into the hole

The disadvantage of this method is that it is not suitable for all cases, for example, if you live on the first or second floor and your house is located far from the tower. It can help you if the signal problems are not too serious. Thus, the antenna is easy to manufacture, but not as effective as, for example, the Kharchenko antenna.

A more complex variation of the can antenna - with a metal connector inside and a wire that extends from it:

1. You need to drill a hole in the jar for the connector. It is better to use a connector with a nut.
2. You need to solder a pin from a piece of copper wire to the connector, the connector is screwed into the can (you need to make sure that it has electrical contact with the inside of the can, because sometimes it is varnished).
3. After this, all that remains is to make a cord to connect the antenna to the modem.

   A can antenna can be made with a cable

Technical data and characteristics

Depending on the range, radio antennas have different designs and dimensions. Designs of existing receiving and transmitting devices:

• "wave channel";
• pin;
• Kharchenko zigzag antenna;
• planar.

The directional “wave channel” has the highest gain among all known antennas. If the distance from the base station to the village is several tens of kilometers, then a parabolic antenna may be the only solution for mobile Internet.

The simplest type of pin is a vertical conductor mounted on an insulator and connected at one end to a receiver.

A panel antenna is a version of a radio antenna that catches a scattered signal. When there are any obstacles, this model is suitable for stable operation of reflected waves.

The universal model of the Kharchenko radio antenna, which can be made by hand, consists of two copper squares, 3.5-4 mm thick. Simple in design, the frame model creates an excellent reinforcing effect.

Frame for dual biquad antenna

The frame for the Kharchenko antenna is made as follows:

• a piece is cut off from the straightened wire, the length is selected based on the size of the device (total 260 mm);
• using platypuses and a verification drawing, the desired shape is given, excess wire is removed with wire cutters;
• in the central part there are two adjacent ends, they need to be soldered so that they do not touch the opposite corner, which needs to be tinned.

Note! The radio wave can be further amplified by increasing the number of frames in the design (amplified biquad Wi-Fi antenna).
This double biquadrat or double WiFi antenna is made with your own hands in the same way as the regular version. A distinctive feature will be that the length of the wire workpiece will need to be increased by another 24.4 cm, and two more frames will need to be added to the drawing on each side. It should also be remembered that for the outer squares there is no central connection, they simply cross each other, and insulation is laid between them.

Depending on the connection method

SMA modification

Several conditions must be met for this modification of the antenna for a 4G router to work for the user:

• 3G/4G modems equipped with TS-9, CRC-9 connectors.
• Models with SMA connectors through which external connections are organized. The modem is already built into these routers. All you have to do is insert the SIM card.
• You will need not only the device itself, but also 2 cable assemblies with SMA connectors, up to 10 meters long. Then it’s easy to enhance the signal quality.
• To connect the cable, it is recommended to purchase two special adapters or pigtails.

Note! The use of this technology is relevant if there are connectors where external devices are connected. You can also use adapters to connect to regular USB modems

But a high-frequency cable in such situations will be too expensive. And losses in signal quality will remain serious. We'll have to strengthen

You can also use adapters to connect to regular USB modems. But a high-frequency cable in such situations will be too expensive. And losses in signal quality will remain serious. We'll have to strengthen it.

BOX modification

The purchase of such products requires the presence of the following equipment:

• USB extension cable.
• Modems for outdoor antennas for 4G modems, supplemented with TS-9, CRC-9 connectors.

Important. At the rear, the device is complemented by a sealed box of small dimensions

Adapters for connecting to a modem are usually already built into this part. A modem with 3G/4G technology is installed inside the box, to the connectors of which adapters are then connected. The next step is to insert a USB extension cable into the box. Usually a special sealed lead-in is used. All that remains is to connect to the modem.

A universal WiFi router with a USB connector and 4G support is needed if you plan to use the Internet on several devices simultaneously.

If the user already has a 3G/4g modem, the BOX modification will be an excellent way to save money. Only the modem limits support from certain telecom operators. The overall stability of operation via a USB extension cable largely depends on specific models.

USB modification

This is a kind of ready-made complex that allows you to amplify signals that are transmitted according to conventional standards. The user does not need any additional devices; a standard set is sufficient for amplification.

Note. A universal 4G modem is already built inside from the start

But 3G standards are also supported. It is enough to connect a SIM card from any operator operating in Russia. After this, the device is connected to the computer. Another option is to use a router together with a USB cable 10 meters or more long.

Signal loss on cables when using USB modifications is completely eliminated, the connection is stable.

Note! Only Ethernet modification devices will be a suitable solution if the connection requires a cable longer than 10 meters

Ethernet modification

Another type of ready-made kits that amplify the signal for modern 3G/4G standards. The kit comes with a built-in 4G modem, which is complemented by a router with a POE adapter. This designation is a technology that allows you to connect regular Ethernet cables. Their length, at the user’s request, can reach 100 meters.

When the connection freezes, the device supports automatic rebooting. Characterized by compatibility with WiFi routers of almost any modification. The rating will help you make your choice.

Note! Signal loss on cables is almost completely eliminated, which already distinguishes this option from the SMA 4G antenna

What types of 3G/4G antennas are there?

Antennas (both purchased and homemade) are divided into several types depending on several indicators. If we talk about the installation method, there are indoor or outdoor antennas. The latter are more effective because they work in open space, where there is less interference. They are suitable for those subscribers who live far from the tower.

Indoor antennas are not as effective as outdoor antennas

Based on the receiving signal, antennas are divided into broadband and narrowband. The first ones are more functional - they are capable of receiving 2G and 3G signals when, for example, 4G does not work.

Antennas are also divided into directional, omnidirectional and sectoral. The last two types are capable of catching signals from several towers at once. There are also conventional devices and MIMO antennas - advanced equipment with two antennas at once, which receive the signal separately from each other, but transmit the signal to the modem simultaneously. They can increase speed up to 100 Mbit/s.

The MIMO antenna essentially has two receivers, hence its effectiveness

Depending on the presence of an amplifier in the antenna, devices are divided into active and passive. Passive ones, where there is no amplifier, do not improve the mobile network signal as much as active ones, but they do not need to be connected to an outlet (the amplifier is powered by an electrical network).

Wire antenna

Another primitive way to strengthen a fading mobile network signal is copper wire. It needs to be wrapped around the bottom of the modem, where the internal antenna is located. About 20 - 30 cm of the wire should remain free. We bend this free piece - it should be perpendicular to the modem, that is, vertical. We place the modem with a homemade antenna on the window and connect it to the PC using an extension cord.

Make a few turns around the modem and straighten the cable vertically

An extension cord can be purchased directly with the amplifier - this will also help improve performance.

Device creation process

First you need to create a vibrator. Size and symmetry are of paramount importance. To give maximum symmetry to the installation, it is necessary to make all the edges of the squares absolutely identical. This can be achieved in two ways:

• Be sure to pre-mark the wire with a marker;
• apply a control template of a certain length.

In the first method, pliers are placed on the wire marking and the latter is bent at an angle of 90 degrees to control the bend along the square.

In the second case, it is necessary to separate a part of the wire on a scale slightly larger in size than the sides of the square, and then sharpen it with a file or coarse sandpaper to the control size. The completed template, together with the wire, is placed in the jaws of the pliers so that one end, simultaneously with the wire, rests against a solid plane, and the other converges with the output plane of the pliers. Also, to guarantee the evenness of the surfaces, you can make calculations online using the Kharchenko antenna calculator specially designed for such purposes.

After this, the vibrator is bent with manual effort, using a control template for each edge of the square. After the wire is completely bent, the remaining part is removed with side cutters. A verification measurement of the faces takes place, which ensures symmetry in the position of each side in the same plane.

Connection and signal transmission options

In the middle of the bottle cap, a hole is drilled with a drill or cut with a knife, slightly smaller than the diameter of the cable (to make the structure more stable). The end of the wire is inserted. After this, it is disassembled so that the central core with a place for tinning and soldering is exposed.

The wires are connected with any soldering iron (you can even use a homemade one). When soldering is completed, the cover is pulled onto the vibrator, moving along the cable.

The reliability of the connection can be increased by using glue and making small cuts in the plastic plug.

The DVD disc is inserted into the cable through the central hole and glued to the end of the plug. In this installation, the reflector and vibrator do not make electrical contact with each other.

The antenna vibrator assembled in this way, together with the reflector, guarantees good reception of the electromagnetic signal wave without contact from the transmitter and redirects it along the coaxial wire. Now all that remains is to redirect it to the modem.

Redirecting the 4G signal to the modem can be resolved in two ways:

• make a direct connection of the coaxial wire cables directly to the modem board;
• use the antenna made by Kharchenko as an intermediate amplification link and use it to transmit the received signal to the integrated antenna of the receiving device.

The first method, in turn, involves two solutions depending on whether the modem has a special connector for connecting to an external antenna or whether it is missing.

If there is a connector, this will save the amateur craftsman from solving additional problems. Then you only need to solder the ends of the coaxial wire to the second part of the connector and connect the antenna through it.

If there is no connector, then to organize a direct connection to the modem board you will need not only disassembling the coaxial cable, but also soldering the core conductor with the screen layer to the microcircuit tracks. This is a very complex and delicate technical work that must be performed accurately, safely and in full compliance with technology. Otherwise, the modem will fail, and then you will have to buy it again.

Send data wirelessly

Anyone can cope with this task. It will be necessary to solder electrodes to the output points of the coaxial wire - they will become a generator unit and will emit a generally accepted and intense magnetoelectric wave directly to the modem antenna. You need to make one turn with any thread along the outer contour of the modem body and measure its size with a ruler. After this, you need to add 5 mm and cut a couple of strips of 75 mm in length and 45 and 27 in width from foil or a tin can.

The wide part for the core core needs to be bent according to the configuration of the modem, and for the screen - in a semicircle, and then soldered to the Kharchenko antenna.

The electrodes need to be separated a short distance and directed in such a way that they produce and address the received magnetoelectric signal to the integrated antenna of the modem. Their best location can be found experimentally.

Now everything is ready. All that remains is to insert the 4G modem into the laptop connector, and then check the quality of the network.

Drawing of a double homemade biquadrat

In addition to the above, it should be noted that when manufacturing an antenna for a certain frequency, it is very important to comply with all the dimensions given below (together with the drawing):

Design features and operating principle of MiMo antennas for 3G and 4G modems

1. the initial value of the angle between the arms of the frame is 90 degrees, then when setting the gap it will change slightly to the desired value;
2. the external length of each edge of the square is 30.5 mm, deviation is permissible within 0.5 mm, no more;
3. the gap between the central bends is 1-5 mm, selected directly during setup;
4. the reflector is made in the form of a rectangle with sides 100 x 120 mm.

Note! Once again, the importance of maintaining accurate dimensions should be mentioned. This means that the antenna must be absolutely symmetrical with respect to its central part, regardless of the length of the edges.