What is GSM antenna. Homemade antenna for phone. How to connect an external antenna to a smartphone. Development of the GSM standard, GSM antennas

Recently, the area coverage with networks of the GSM 900 standard network has significantly increased. Nevertheless, the situation is far from ideal. If in European countries the problem of unsure reception is practically absent, most of the domestic users often face it - in country houses, in dachas, etc. And how it would be wonderful to go fishing, hunting, in the village, without losing touch with the outside world !

The key to solving this problem is external directed or non-directional antennas. True, it is not enough to buy an antenna - you need to install it correctly and configure. Readers familiar with radio electronics can independently make and configure an antenna running in the GSM standard. Today we will tell about the types of antennas and the methods of their installation and settings.

reference

It is quite simple, a mobile phone is a duplex radio station leading radio exchange at different frequencies. Total in the GSM 900 124 frequency standard. The phone, like the base station, can work at any frequency defined by the operator.

The base station (BS) transmits, and the phone (MS) takes at frequencies of 935.2 - 959.8 MHz. Mobile phone transmits, and the base station takes at frequencies of 890.2 - 914.8 MHz. Channel from BS to MS is called Down Link, from MS to BS - Up Link. Most operators use a limit of a mobile phone's range from the base station - 35 km, due to the characteristics of the standard. We explain that 8 time intervals (time-slots) are formed in the standard configuration network (time slots): one service, and seven - conversational. It is in this case that the maximum range of communications on each channel is 35 km. However, the GSM also provides a non-standard cell configuration, in which the communication range increases by 70 - 100 km (EXTENEDED CELL configuration). Unfortunately, with such a configuration, the number of conversational channels decreases to 2 - 3, which reduces the capacity of the network. Use such a mode in the city and is not profitable about the operator. Sometimes this mode is used on the sea coast to create a coastal coverage area.

Thus, if you have a GSM 900 phone standard, do not attempt to establish a connection by removing more than 35 km from the nearest base station. The maximum range of communication reached by me is 34 km.

Communication range

The following factors affect the range of radio communications:

Location BS and MS and terrain relief.

MS power and sensitivity.

Power and sensitivity BS.

Used on MS and BS antennas.

The will of the Lord God (experienced communicationists joke, that this is the main thing).

Typically, base stations have a power of 20 - 30 W. Antennas are applied either pin or directed. The sensitivity of basic stations is -100 dB - 115 dB. Edit or influence all these parameters, the user, of course, cannot. The output power of the phone is 0.3 - 2 W, sensitivity - 90 - 105 dB. The sensitivity of the phone is mainly determined by the technologies used when creating low noise input devices. If in the zones of confident reception, the difference in sensitivity and power between models is almost imperceptible, then in the zone of uncertain reception, it can be critical. Often the tube shows the signal level from the base station 1 - 2 cubes (on the scale), and the connection cannot be installed: there is not enough power. And although the standardization of ETSI regulates the standard output power for each class of phones, the actual value can slightly fluctuate. Good sensitivity is different tubes Sagem, Alcatel, Motorola. And in power there are all old phones, especially Motorola. All phase 2 phones are about identical power.

As for the relief, on the level terrain and the wave river are better distributed. The higher you are (within reasonable limits), the better the signal. The forest sometimes "quenching" the waves is stronger than the city building.

Signal search

So, you got out of the city and want to ensure ourselves. Climb the roof, the attic or the highest point next to the house or the place you need. If the phone catches the network, but at the limit (or unstable), you have every chance to correct the case using an external antenna. If the distance to the station is less than 30 km, and the network is not caught, also try to apply the antenna. In the latter case, try to agree with the sellers of return antenna if the experiment fails.

If the signal, though very weak, was still caught, type any urban number - to check. If, when conversing audibility, the normal and interlocutor does not complain about the loss of pieces of your speech, then the energy of both lines (UL and DL) is balanced and you can use a standard antenna configured to the middle frequency between reception frequencies and transmission. If the interlocutor disappears from time to time, it is necessary to "enhance" a downward direction from the base station to your phone. It is possible to look for a phone with better sensitivity. But if you do not hear you, you should strengthen the direction from your phone to the base station. Already at this stage it is clear that when choosing the type of antenna and its parameters it is desirable to consider the operator data and the reception conditions.

In the zones of uncertain reception, interference (interference) is often observed between channels with the same and adjacent frequencies. Unfortunately, the frequency resource allocated by GSM 900 operators in Russia is limited, because of which the frequencies from different base stations with the same or adjacent values \u200b\u200bof the signal level are often "visible" in the unsure reception area. Such frequencies create mutual interference, interfering ties, and at certain levels of signals, the connection becomes at all impossible. If a strong signal from the base station is recorded on the phone screen, and the connection cannot be installed or managed, but it all disappears all the time, it means that you encountered "strangers". "To force" the phone to choose another frequency is far from always, however, the special function of the Nokia phones is NetMonitor - it allows it.

With a similar problem, I ran into the country, which is separated from a large city rather open space. The phone took the adjacent frequency channels with levels of 70 dB, 73 dB and 72 dB, but the quality of communication left much to be desired. Saving me only forced choice of another frequency channel with a smaller level - 80 dB. However, with a limited frequency resource, even frequency redevelopment of the network cuts far from always. Nevertheless, if NetMonitor is missing in your phone, you can use an external directional antenna with a good orientation diagram. It remains only to make the right choice.

Select antenna

As already mentioned, external antennas allow increasing the range and communication quality. For phones, external pin and speakeriodic antennas are mainly used, as well as antennas such as a wave channel. We repeat that in Western Europe there are no zones of uncertain reception. Therefore, directional antennas for GSM 900 terminals are practically not available. If the manufacturer offers a GSM 900 directed signature antenna, it is usually designed to work with repeaters (repeater) operators.

In the CIS and Eastern Europe, directional antennas are manufactured by a handicraft. In addition, there are not large bids in the Czech Republic, Poland and the Baltic States. A simple automotive magnetic antenna has a gain of 1 - 3 dB (1 - 2 cube on the phone scale), a wave channel - 7 - 15 dB (depending on the number of elements, the quality of assembly and the antenna settings), which is already 2 - 3 cubes on the scale , and the logoeriodic antenna - 7 - 12 dB. The car antenna is a vertical pin in 3/4, 1/2 or 5/8 wavelength. Even a simple automotive antenna raised higher, can correct the situation with a uncertain bond. The fact is that when talking about 10 - 20% of energy is absorbed by the user's body, therefore, lifting the pin antenna upwards, you reduce the effect on it surrounding items. I myself observed how homemade, half-wave and vertical dipole raised at 5 m, solved the problem of communication. Let us explain how such a dipole is manufactured.

Fig. 1. Vertical dipole

We clean with one end white RG6U television cable. We get a central conductor and cable braid. A copper wire of any thickness of about 8.2 cm (for a 900 MHz range) is soldered to the central conductor (for the 900 MHz range) and it is configured vertically upwards. To the braid we solder the second piece of the wire of the same length and secure it vertically down (Fig. 1). We get something similar to the letter "T", the laid. (Horizontal polarization is used in television, and in GSM - vertical, so it is necessary that kind of dipole.) The other end of the cable is connected via the adapter to the phone. Be careful and do not close the central core with the braid, otherwise the phone can burn. Well, in 5 minutes we have built a primitive antenna that is not inferior by the parameters by Chinese car.

I will give a story from life. Having arrived in the past summer to rest in the Crimea, I found that there is no confident coating on the basis of the operator. This meant that I would miss a very important call. A confident signal was found on the roof of the cottage, but the prospect of seeing there for two weeks did not inspire me. In 5 minutes I found a piece of the desired wire (instead of copper used aluminum). Another 10 minutes went to find a 5-meter piece of a television cable from the neighbors. Nokia 7110 has a mechanical switch for an external antenna, so I just stuck the central cable conductor directly into the phone connector, and the cable braid connected to the metal rim of the external phone connector. He strengthened the antenna on the roof of the house and after 10 minutes to the joy of the family and on the envy of the neighbors fondly talked on the phone.

As they say, back to our branches. First, use the automotive pin antenna ($ 5 - 10).

Here the main thing is not to run into too bad quality. Having NetMonitor, check the antenna is much easier. When the automotive antenna connected to the telephone, the signal level should increase by 1 to 3 dB (for example, from -60 dB to -57 dB). In extreme cases, the signal must remain the same. If when the antenna is connected, the signal will decrease by 5 dB and more, it is better to abandon the purchase. I want to note that a good branded car antenna costs from $ 40 and higher. However, among Asian 10-dollar products sometimes there are good things.

Mounted on the roof of your "house in the village", the car antenna is able to solve the problem with communication. If the amplification of the automotive antenna is not enough, you can turn to others - for example, to a common directional antenna - a wave canal. It looks like an ordinary television antenna installed on the roof of the house.

The wave channel allows you to get a real amplification of up to 7 - 15 dB with an optimal orientation chart. But he has a flaw - narrow-band. The difference between the reception frequency and the transmission frequency in GSM 900 is 45 MHz, and the entire operating range is 890 - 960 MHz (80 MHz band). To achieve a linear or close to linear characteristics in such a wide range is difficult. Therefore, it is desirable to make a wave channel depending on the frequency of the operator and a particular place and, depending on the situation, shifted the resonance to the frequency of ascending or downward directions. For greater broadband, only the loop vibrator should be used, coordinating it with a cable - for example, with a symmetrical loop; You should also restrict ourselves to a small number of items, say, 3 - 12, as if there are more of them, set up an antenna without equipment will be difficult, moreover, the operating range of the antenna is narrowed.

I had to deal with a variety of wave canals made by treasurely. Ascertain: in most antennas, the gain accounted for less than 7 dB, some had a resonance at frequencies of 700 - 800 MHz instead of the GSM band and a standing wave coefficient greater than 3 (during transmission it can easily deduce the output cascade of the phone). Professionally made and customized homemade antennas were rare.

Now on the queue - logoeriodic antennas (they can also be found on the radio launch). Compared to the wave canal, they have a wider working range. Therefore, such antennas are less critical to the accuracy of manufacturing and setting. Real gain here reaches 10 - 14 dB.

Theoretically, if necessary, you can connect 2 wave channels, one-tuned to the reception frequency, the other - to the transmission frequency, but this is too complex system.

Cable and antenna adapters

In the 900 MHz range, the selection of the cable acquires a paramount role. Domestic television coaxial cables can only be used limited (attenuation of more than 30 dB per 100 m is too large). From the available imported samples will suit RG6 - a coaxial cable with a double braid. You will find it in any store. The attenuation is 20 - 24 dB per 100 m (checked experimentally). Industrial pin car antennas typically include a RG59 cable with 28 dB at 100 m. The antenna of the wave channel type with a gain of 12 dB and 10 m of the RG6U cable gives a general amplification of 9.6 dB, and at 20 m - 7 dB.

Most phones have an external antenna connector. In addition, for each type of phone, there is a so-called antenna adapter (about $ 5), it connects to the specified connector and is a short cable piece, on one side of which a specific telephone high-frequency connector is located, and on the other - the standard RF connector. Usually attenuation in the antenna adapter does not exceed 1 dB. Buying an antenna adapter, make sure that it is possible. When the adapter is turned on, the antenna built into the phone is turned off and the output cascade switches to the adapter. In other words, if you simply connect the adapter to the phone, the signal on the phone scale should drop a little. Then you connect an external antenna to the adapter, and the signal increases. If everything goes exactly that, it means that the adapter works.

Configure antenna on the ground

So, you bought an antenna and connected it to the cable and to the phone. We rose at a high point and started setting up an antenna. Place the phone so that the screen is visible. As already mentioned, when setting up an antenna with Nokia devices, it is best to use the NetMonitor feature. In most other phones, you can enter a special code and open a service menu that allows you to see the receiving level 6 - 8 frequencies received by the phone in descending order, the number of frequency, distance to the base station, the percentage of errors in the channel, etc. (description of many service menus, cm . To: www.3ton.com/gsm.) If NetMonitor is, we will navigate the signal level in decibels (we remind you that the signal is stronger when the level in the decibels is less). If it is absent, we will be adjusted according to the standard signal scale.

Since the antennas of GSM 900 base stations have vertical polarization, the wave canal should be placed vertically. When adjusting the antennas, note that the receiving level of the signal displayed in the phone varies with a delay of up to a few seconds, so the antenna should be rotated slowly and discretely. If you know the direction to the nearest city, start with it. Slowly turn the antenna by the horizon. If the signal is found, your task is to find the direction from where the signal comes from the maximum level. If there is no signal, slowly rotate the antenna by the horizon until it appears. Remember that each meter of installation height of the antenna may be decisive. If the signal is not found, try moving a few meters to the side and search again. Maybe you will be lucky.

It is unwanted to use a cable between an antenna and a telephone longer than 30 m: In this case, almost the entire signal is lost in the cable.

Finally, we present the dimensions of the self-made logooriodic antenna for the range of 850 - 950 MHz (Fig. 2). Dimensions taken from www.atnn.ru. The program for calculating an antenna-wave canal again can be found on: www.3ton.com/gsm.

Parameters: A amplification coefficient - 8.3 dB, wave resistance - 60 ohms.

Do I need to acquire an expensive gadget when it is possible to do with the device collected from the remedies?

Those who have at least the initial level of knowledge in the field of cellular communications will be able to cope with themselves. This requires components and tools, as well as a device diagram.

And you can collect the simplest cell amplifier on your own. The fact that this will be required to be described below.

Antennas for increased cellular communication

They are one of the simplest devices that allow you to achieve a high-quality signal on any object.

There are two main groups of antennas:

External;
Internal.

The first is usually installed on the roof of the building and are able to provide a coating on the objects of a large area. The antenna signal received from the base station transmits the cable to the amplifier. This guarantees a good quality of communication even in zones where it was previously impossible.

What elements a signal amplification system consists

Provide a reliable connection to the places hard to access the radio signal, it is possible for this, it will take special equipment. Various devices collected into a single system allow you to achieve high quality signal and forget about its sudden disappearance forever. Often it is called cellular amplifier. However, in fact, this is a complex consisting of the following elements:

Repeater or double-sided amplifier, which is an intermediate link;
External and internal antennas that capture the station signal and distribute it indoors;
Power divider or wire splitter;
N-connectors;
Coaxial cable resistance 50 ohms.

All enabled devices are divided into two groups:

Active;
Passive.

The first includes devices for which the connection is required to the power source - this is a repeater, connectors. Passive call antennas, divider and cable. Each system is calculated under a certain object and therefore may have a different amount of amplifiers and internal antennas. The optimal option is considered to be the minimum length cable, since each excess meter is a loss as a signal. This must be considered by collecting cellular signal amplifier with your own hands.

Since all items are connected to each other, the installation of the equipment is recommended to perform before finishing, not to spoil the interior.

Principle of refirator operation

The equipment of this class in some kind is the repeater. It processes the signals received and directs them on the basic storage tower if it is the outgoing call. When the subscriber is dialing, the repeater performs the same function, only the connection is carried out with the user's gadget.

We watch the video, the simplest way to enhance the signal:

Reception and signal transmission are carried out antennas. The most simple cell network amplifier can be collected with their own hands. The outer antenna receives or sends it to the station, and the internal is responsible for expanding the area of \u200b\u200bthe coating area.

How to make a cellular amplifier with your own hands

The use of such an appliance allows you to achieve high-quality communication in almost any corner of the object. Especially needed by repeater in zones with a bad signal or where it is missing. The benefits of using the system can be attributed to such as:

Enhancing the signal in places where there are frequent interruptions with mobile communications;
Elimination of interference;
Increasing the clarity of the message;
Reducing the level of radiation;
Long service life of the phone batteries.

But since such equipment is not cheap, many are decided to make it yourself.

We watch the video, the stages of manufacture with your own hands:

In order to collect a cellular amplifier on its own, the components need to be connected to a single system. How to do this will be discussed below.

What is needed for assembly

If you decide to make the easiest device, namely the antenna, then you will need:

Wire, but not copper (length 30-40 cm);
Connecting block;
Cable (up to 10 m);
Fasteners (for mounting connecting blocks);
Polymer pipe (20 cm);
Plastic.

Because in the process of work, you will have to connect individual elements, then it is necessary to have a tape at hand. After all components are found and prepared, you can proceed to assembling the cellular signal amplifier with your own hands.

The wire segment must be bent in the middle of 90 °, so that the rhombus is in the end. For this, the center is retreating 9 cm in both directions. Then, in place, the wire marker again bends on the same in the amount of the angle. As a result of the manipulations produced, you get a rhombus. The ends bend inside and the block is connected to them. It is installed so that in the future it can be connected through it. For this, it is cut along one side of the polymer pipe and the hole is performed on the contrary.

We watch the video, make an amplifier from cans:

After the antenna assembly phase is passed to connect the coaxial cable. At one of its ends, external insulation and external and internal conductors are connected to the contacts of the connecting unit. As a result, the cable becomes a continuation of the antenna.

After that, it remains to install the device on the roof of the house or attach to the post and direct it towards the base station of the cellular operator. The last step in the manufacture of the simplest amplifier with your own hands is the connection of the other end of the cable to the plastic plate. And you can proceed to testing.

If everything was done correctly, then as soon as you bring a mobile phone to the amplifier, the signal indicator will increase by 2 or 3 divisions.

Choosing a Repeater Installation Places

But only little to collect a cellular amplifier, it is also necessary to correctly fulfill its installation. The efficiency of such equipment is directly dependent on the location of its location, as well as the antenna system. Therefore, before starting to install, you must make sure that the signal level is sufficient. The easiest way to know is by having a call from the phone where the antenna is planned. You can determine the level of the signal and on the indicator on the gadget display.

Install antenna

But besides this there are other limitations. For example, a place to install the amplifier should not be closer to the meter to heating instruments.

After the planning of the location of all components is proceeded with the coaxial cable laying. But before turning on the repeater must be verified in the integrity and purity of all connectors. You can not include the device if it is not connected to the external antenna, as it may fail. If you need to disconnect the radio frequency cables, you must definitely turn off the power.

There are limitations in the temperature mode. If it is from -40 to + 50 ° C for the outer antenna, then for the repeater itself is limited only to positive temperatures. In addition, the repeater can only be installed in a heated room.

Need to remember! The incorrectly assembled system can emit interference, which affects the work of the nearest stations. Therefore, it is not necessary to establish it without an object examination and determining the place to accommodate all blocks.

Adjusting the amplifier

To get a stable and having a sufficient level of communication signal at a specific object, you must correctly perform all commissioning work. They are to configure the quality of voice messages and the exclusion of self-excitation of the device.

We look at the video what to do if a bad signal, we look at the solution:

The first from which should be started is to make sure that all connections are integrity. The power and antenna adapter is connected to the high-frequency connectors. If voltage jumps often happen in the network, then it is necessary to use a network filter.

The next step is to adjust the gain. It must be at least 15 dB. The repeater setting can be carried out in manual or automatic control. In the first case, the adjustment is carried out using the potentiometer handle and changes in the position of the external and internal antennas.

Automatic setting involves setting the gain coefficient in such a way that the maximum output power is obtained. In this case, the device will independently adapt to the traffic of the operator base station.

We live on the edge of a small village. Faced with the need for the Internet at home, began to study that in this sense the modern infrastructure offers.

It turned out that the most affordable and easiest way to connect to the World Wide Web is a GSM modem, inexpensive options for which, often name a USB whistle. Such a modem is inexpensive, it is widespread and works well, but, only in the zone of confident receiving signal, the base station of the cellular network. In the city - be kind, and outside it, it strongly depends on how developed the mobile network is. Often for the modem requires a good external antenna raised to some height. Models of devices with connectors for connecting an external antenna are considered a certain, professional connected device and are ten times more expensive.

To work, you will need a minimum set of radiomontal and plumbing tools, tool patience. To work with the trifle, a special visor with magnifying glasses or lamp with them is very helpful. Take care of good lighting.

However, in the simple "USB whistle" inside the case there is a technological connector for antenna and you can use it. In some modems, there is access to the antenna connector, in some no, in the latter case you will have to refine the plastic case, the device warranty is canceled accordingly. The antenna connector of the budget modem is very harlocks in design and installed directly on the printed circuit board by surface mounting. That is, it holds only for solders.

It should be connected to it only a rather thin (flexible) coaxial cable, otherwise the likelihood of a thick and hard cable to break the connector is high. Thin cables have increased losses on HF and should not be used for the entire feeder. In principle, there are adapters - a modem connector - 15 ... 20cm of a thin cable - a more connector for connecting a decrease in a good external antenna cable. Such an adapter allows you to solve the problem of mechanical load on a weak connector, but we turn out to be tied to a specific connector at the output of the adapter, which in the case of a homemade antenna is unreasonable, moreover, such adapters are found extremely rare on sale. It is worth remembering that every additional connector, even every soldering on the cable, makes attenuation on the RF.

My connection option - a fairly flexible television cable came up in the store - without a foil screen, the central lived copper (well soldered) and stranded (flexible). Connection looked like this.

A segment of copper thick tiny wire (leg of the resistor) is soldered to the central custody. Its thickness is such that it fits tightly into the nest. Cut place is insulated with thermal tube.

The pin is inserted until it stops into the connector and the twisted and tinned cable braid solder to the "earth" of an antenna socket.

The soldering place is isolated, and most importantly - a thin seat on the cable is amplified by several layers of thermal tubes. Now it remains to try and, if necessary, cut the plastic case, so that it is closed as it should be, with our refinement. You have to go carefully.

All, the modem is connected.

Go to the calculation and manufacture of antenna.

The type of antenna, selected "logooriodic", adopted by foreign abbreviation - LPA antenna. Its features - a high gain and very narrow (acute) orientation diagram. In addition, with a sufficiently neat manufacturing, the antenna will not require the setting that cannot be carried out without specialized RF measuring instruments.

We prepare the necessary materials and tools. At the first stage, we need to cut two strips from one-sided foil fiberglass 10mm wide, 1.5-2 mm thick, and long - according to the calculations. We will also need trimming of the "naked" copper wire with a diameter of 1.5-2.5 mm, which can be removed from the cable for the internal wiring. Well, respectively, the soldering iron, rosin, ruler and nippers.

Cut the elements of the same size, 5-10mm more than the longest vibrator, referring to the calculations produced. Location the location of the antenna elements on the improvised "boom". Next, we carefully solder them, not overheating the substrate, and the impressions are brought to the required sizes. It should be remembered that we are dealing with RF with its skin-effect (the spread of currents in a thin surface layer), in this sense, should not be allowed to be allowed by "cold swabs" and strongly scratched surfaces. Good tone is the use of a special flux with glycerin to obtain a mirror surface of the bucks.

Now, you need ready-made "booms" to rigidly firmly opposite each other at the calculated distance and close the rear parts with a jumper. A coaxial cable is connected to the front ends - to one end central lived, to the second shielding braid.

My execution of the antenna is on the polypropylene tube. A suitable piece of pipe was pile on a circular saw to produce flat sites that are comfortable for fastening Half "boom". They were attached with a sticky tape. Behind the antenna place for the modem - initially it was decided to shorten the antenna cable as much as possible, the modem is located near the antenna and the decline to perform already "digital". The plastic tube is taken somewhat longer, to obtain a convenient dielectric "handle".

Another antenna antenna, visible seats of boom halves, connect the cable. I recommend to get acquainted with, perhaps a more successful design of the antenna.

The finished antenna for performance test was carried out on the street and fixed at the end of the long staircase.

Due to the inconvenience of orientation, I had to make a swivel knot. Some plumbing works, stainless steel trimming, welding.

The swivel knot was released somewhat cumbersome, but unlike a similar node, the satellite dish allows you to orient an antenna significantly more accurately.

The rotation knot is welded to the attachment plate at an angle of just over 90 degrees (so that water flows). During work, stainless electrodes ended, had to use ordinary - hence painted welding seams. In the photo above, the knot, which worked on the roof in different places, with different antennas, for about two years and as a whole, which has also provided itself with reliable and convenient.

On the photo of an antenna with a USB modem installed on the roof front. The angles of rotation allow you to orient an antenna on a cellular tower in the next village (~ 5km).

In a hermetic box next to the antenna, modem, and a modem power supply. In general, the entire circuit of the connections looks like this.

The problem of long USB compounds - in the fall of supply voltage on long and relatively thin power wires (the principle of operation of the device via USB port - including the power of the device from the port itself). Under reasonable limits to lengthen the USB cable, in two ways - to increase the section (reduce resistance) of power conductors or feed the device from its closely located power supply. The purpose of both ways is that the supply voltage can be more close to five volts on our device. A plus.

An increase in the cross-section of the feed wires was already tested under the trial inclusions of the antenna "on the stairs". The connection and access to the network were, but it was not stable - periodically broke out.

To accommodate an antenna with a rotation node, another place was chosen - the front of the roof of the house. The distance to it is somewhat larger and the power supply was solved to place "upstairs" - near the modem, removing the possible cause of failures. The "long" USB connection was made of two non-body coaxial cables (central cores - two data lines, screens to a common wire).

What happened - placement on the front of the roof (access with a flat roof of a short staircase in a short staircase) and the overall configuration of the equipment allowed, in consequently, it is convenient to experiment with different types of antennas. At that time, it was possible to connect relatively steadily to the GSM network (2G), sometimes WCDMA (3G). The antenna itself showed itself well. Some fruitfulness of manufacture (many exact sizes) pays off in lack of configuration and greater amplification. Antenna also has low sailboat and little attractive for birds.

Running forward. The reason for the unstable work of the modem, it was still a long USB cable, despite the well-being with the power supply of the device. Perhaps the case was in the type or even instance of the modem, because the network includes descriptions of such "extension cords" and more in the larger.

Manufacturing and testing of two more types of antennas will be described separately.

Often in the countryside, the signal level from cellular taps is low, and we see only one or two divisions on the phone. But there is a simple way to enhance the signal without buying expensive 3G amplifiers. In this manual, we will create a 2G / 3G / 4G signaling signal for giving up to the girlfriend. This amplifier will be able to increase the level of the signal in the house from one division to the full scale. To do this, you need to build two modules - one outside the house and one inside. Both are the same and easy to create, the assembly will take about 1-2 hours. Before starting work, put on protective glasses and gloves. LTE antenna was mainly designed to enhance the E GSM 900, 2G signal. To obtain significant results, you need at least to catch at least some signal on the street.

Show more images

Use the homemade antenna for 4G modem to your risk.

To begin with, find the necessary components:

Iron hanger 2-4 mm thick (be sure to check with a magnet that it is made of iron). It will suit any iron wire, the absence of paint will increase the efficiency of the system.
Two blocks for connecting the cable (20A, if you find this).
Conventional cable: - TV cable, coaxial, from satellite TV (you need 30 m of a good quality cable, not cropped, not from the connected parts).
Wire scissors.
Pliers.
Sculpture.

Step 1: Let's proceed to assembling a remote antenna

Look at the drawing. The first section, which we collect from the old iron hanger, will be an antenna 3G. It is marked with black. It is not necessary to extort the external paint for it.

Align the wire with pliers (or hands) and bend at a distance of 4 cm from one end at an angle of 45 degrees.
Then, measure 8 cm from the bend and inside the wire inside 90 degrees.
Next again, measure 9 cm and make another fold 90 degrees inside.
The last fold will be the same as the first - by 45 degrees, here we will install a block for connecting cables. Install the block on both ends of the cable and secure it.

Wires are connected inside the connector block. Plots 4 cm long need to be cleaned from the patch \\ paint. As a result, you need to collect two identical modules.

The next step in the assembly of the GSM signal and the Internet signal amplifier will be a wireless antenna, highlighted in the figure orange and yellow. For this site we will need a regular TV cable. First cut about 15-20 cm top cable coating. You will see the shielding coating, it is metallic and looks like a network. Cut it, but do not throw it away - it will be used as a material for the red plot in the picture. Just twist it and cut it if its length is too big. Then install it in the connector block and secure (the form in the form of the letter U is not required - the connection itself is important). Then return to the cable core, carefully cut the insulating layer - to create a 4G directional antenna, we need a bare cable.

Let's look at the drawing again. At a distance of about 5 cm from the beginning of the core, we need to make 5 turns clockwise. You can wind the cable on the screwdriver with a diameter of 3-6 mm. The rest of the core core should be smooth. Now you need to connect our wireless antenna with an antenna 3G. To understand how to do it, look at the pictures. Remember that we need to connect an antenna core with an iron wire and consolidate them in the connector.

After some studies, I came to the conclusion that 7 turns of the cable on the outer antenna and 5 turns on the inner side are best suited to enhance 4G. Use your smartphone to determine the place with the best signal 4G - place the external antenna in this place. A good signal level is determined by about 3 divisions on the phone, the unstable signal is very often jumping up and down.

If, after assembling the antenna, the signal remains weaker, try using samples and errors to choose the best number of turns on the antenna for you. Usually the best signal is caught on the roof of the house or not far from the roof. Internal antenna Place where you will be more convenient - in a vertical position, best under the ceiling, indoors in which you are doing business, as well as at a distance from the wireless router. For ease of antenna setup, I advise you to switch the phone to 2G mode. If zipper hit your home, place the antenna in a safe place. Also, to enhance the signal, you can try to remove the cover from the phone - it is often unpacked part of the signal.

Uninsulated parts of the antenna should not touch the walls and conducting surfaces.

Step 2: Supplement

To enhance the signal, you can try to cut a piece from the kitchen foil length and thickness from about the phone and stick it on the left or right side of the phone (or try to hide it inside the case for your phone). Also as an antenna, telephone headphones can be played - many people noticed that the signal is better with them.

Step 3: Additional Wire

Look at the photo above. I added an additional wire to try to increase the coverage area of \u200b\u200bthe internal antenna. I received this result by the method of trial and errors: you need to take an additional wire with a length of 30 cm, leave about 5 cm on one side and make 4 turns around a pencil, and then connect this wire with the connector. But this improvement will not increase the power of the signal.

Step 4: Version 2.0

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Version 2.0 is more like science fiction. She has more promising indicators, but it still needs to be installed in place with a stable signal. If something becomes incomprehensible - see photos.

Assembly, part 1.

Align the wire from the iron hanger.
Make a bend at an angle of 45 degrees at a distance of 4 cm from the end of the wire, clean these 4 cm from the paint \\ coating.
Measure 8 cm from the bending and bend the wire inside 90 degrees.
Measure 9 cm after that the bend and take another fold 90 degrees inside.
Next again, measure 9 cm and make another fold 90 degrees inside
At a distance of 8 cm Make another flex 90 degrees inside.
Rotate the wire 90 degrees.
Measure 9 cm from the bend and bend the wire inside 90 degrees.
Measure 10 cm after that the bend and take another fold 90 degrees inside.
Next again, measure 10 cm and make another fold 90 degrees inside
Measure 11 cm from the bend.
The last bending is the same as the first - by 45 degrees inside. From it, too, you need to remove the paint \\ coating.
Grind the ends of the wire in the connector and hold them.
It will be an internal and external 3G antenna collected in one.

Assembly part 2.

Take the 3G antenna we did at the beginning of the leadership (yellow)
Bend the antenna wires at 90 degrees.
Secure the antenna in the connector, as shown in the figure.

Assembly part 3.

The wireless antenna has almost the same design.
It will have 7 turns for an external module and 5 turns for the inner module.
It should reach the antennas described in the "Assembly part 1" paragraph, so it will have to push through the connector.
After successful assembly, fasten everything.

Step 5: Antenna Modification for Wireless Routher

That's what I did with my wireless router DLink 2750E ADSL N-300. I was able to achieve a small modification of the antenna through a solid concrete wall through a solid concrete wall. You can also try to make this trick.

What can be less disappointing than the absence of a stable cellular signal when it is necessary. Fortunately, having the necessary tools and materials at hand, it can make a cellular signal amplifier, including for 3G devices, without much effort and any significant costs.

Why break the piggy bank for the purchase of another expensive gadget when acceptable results can be achieved using the screwdriver? It is only necessary to find the necessary components and combine them together accordingly. Of course, if you need a guaranteed result and it really is of paramount importance for you, then in this case you should purchase a GSM signal amplifier in a special store or via the Internet, for example, in the Mymplifiers online store.

1. Required materials

To build a simple signal amplifier, you will need only six inexpensive components:

Iron wire (35-38 cm long, do not use copper)
Double connecting block for wires
Coaxial cable (no longer than 9.75 m.)
Bolts and nuts (sufficiently long for fixing connecting blocks)
Segment of the plastic pipe (15-20 cm)
Piece of plastic

And a bit of the tape (it is never excess).

2. Assembling antenna amplifier

Using pliers, first straighten the iron wire, and then bend it 90 degrees right in the middle. From the central fold, mark approximately 9 cm. In each direction and take another two 90-degree bends. As a result, you will have a rhombus. For two more folds, mark another 8 cm. And get the remaining ends in parallel inside the rhombus. Screw to these ends the connecting block for wires in such a way that then two wires can be connected through it through it.

Cut one side of the pipe along, and directly opposite the cut, drill the hole and use the bolt and the nuts to attach a connecting block for the wires to it, to which you have attached an antenna before.

3. Connecting a coaxial cable

Remove the external insulation from one of the ends of the cable, without damaging the insulation layer between the external and internal conductors. External conductor Connect to one connector's contact, and the inner to another, so that each of them becomes the continuation of the ends of the antenna itself. Attach the antenna you created to the post, where your TV antenna hangs, wrapping the plastic pipe cut earlier on one side around it. Ensure that the antenna amplifier is directed in the same direction as the television antenna.

After that, make another end of the cable into the room, clean it from isolation, as the last time, just now you can get rid of the external conductor layer. Next, cut out a piece of plastic necessary forms and make it a small hole in it and the wire in it. Now you come in handy a tape in order to secure the wire.

4. Test the amplifier

To test the GSM signal amplifier collected by you, simply bring the plastic thing to which you connected the displayed cable, to the mobile, smartphone, tablet, or 3G modem and the signal indicator should instantly increase by 2-3 divisions.

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