Antenna adapter for cell phones with their own hands

Caring son made antenna for smartphone in 5 minutes, now the signal is as if there is a tower nearby

A cellular antenna in a smartphone requires a coaxial cable that has a high-frequency connector. This is because most mobiles operate in this frequency range. Note that the effectiveness of signal amplification depends directly on the quality characteristics, as the connector itself, and the cable products used. If the phone is not equipped with a jack to connect the antenna, you can use a handsfree device to solve the problem. In addition, you can use the uncomfortable way for the user by wrapping the cell phone with several coils of antenna wire. Although in this case it is rather inconvenient to use the device, nevertheless it allows to achieve a good signal reception in the phone.

Artisans managed to improve the reception of GPS signals on smartphones, using a homemade method. Soldering to the square contact GPS multicore copper wire, which is then neatly attached to the perimeter of the device.

Describes how to install passive GPS antenna with male MMCX connector. It is rather difficult and requires certain skills in soldering. And you should choose a passive receiving device, because installed inside the case the active GPS antenna for smartphone is not suitable. It needs to be powered within 3-5V, which is unrealistic. The battery under such load will be discharged very quickly. In stores more often it is sold as an active antenna.

3G antenna design

Setting up the antenna is very simple. I attached it to the wall of the house and pointed to the side, where as I knew, there was a 3G station, and simply rotated around the axis and vertically, until I saw in the left bottom corner of the interface of MegaFon Internet registration in 3G protocol. A program that you run whenever you want to connect to the Internet, and with which you control the connection (balance check, traffic count, SMS sending, etc.). Д.), in my case it is MegaFon Internet, has a network indicator in the lower left corner. If this indicator shows EDGE or GPRS, your internet speed will be no more than 128 kbit/s. It’s not 3G. If the modem registers in 3G, the indicator will display HSDPA or WCDMA protocols. HSDPA (High Speed Downlink Packet Access). WCDMA (Wideband Code Division Multiple Access). Wideband Code Division Multiple Access. Modem work in the standard WCDMA allows it to send and receive data wirelessly at speeds up to 42 Mbit / s, but remember that my modem Huawei E1550 allows you to work at a speed of no more than 3.6 Mbit / s, which is enough for a normal Internet. In addition, the tariff plans of operators limit the speed, according to the principle pay more money, get more speed.

Without using the antenna, my 3G modem showed full EDGE antenna on the indicator, respectively, the data rate did not rise above 128 Kbps, and the page of Yandex was loaded 1-2 min. My goal was to get a stable 3G signal. With the help of the satellite dish it was possible to do it. The modem showed a confident registration in the WCDMA standard, sometimes slipped the HSDPA. As a result we got a completely different connection speed.

When adjusting the antenna, an important role can play the height and line-of-sight conditions between the tower and the antenna, the presence of many external obstacles will affect the signal. The altitude could help, t. Е. Antenna elevation over obstacles. Therefore, for definition of exact place of fixing of the aerial, it is necessary to try to define it experimentally, holding the aerial in hands. As it is possible to collect such aerial on the basis of a reflector from the MMDS aerial, and in following articles of the blog I shall necessarily tell about construction of such aerial therefore subscribe to RSS not to miss the interesting material. Good luck in your experiments, and if you have any questions, I will be happy to answer them in the Комментарии и мнения владельцев or on the forum.

Additions to the article.

It is better to track 3G signal quality with special MDMA and Wlan Expert programs.

Kharchenko antenna (bikvadrat): simple step-by-step instructions

Scientist Kharchenko has offered this model of the loop antenna in 1961. It was used as a receiver for TV broadcasts. The antenna is very effective. It acts as both a receiver and an amplifier. It is broadband, capable of increasing the signal power up to 3. 4 dB with no reflector and up to 8. 9 dB with a reflector (a metal panel that reflects the signal). It does not matter if it is 3G or 4G.

Its minus in complexity of manufacturing in comparison with the previous self-made antennas. However everyone will be able to cope with its creation if he/she has the necessary desire:

First make a “figure of eight” from a monolithic wire with a cross section of 4 mm 2. The squares should be as equal as possible. There must be clear symmetry. To achieve this, before bending conduct a marker on the wire. Put then the pliers on the wire marking. Now you need to bend the wire at an angle of 90 o. Use the angle piece to get the exact angle.

Make a symmetrical “figure of eight” out of copper wire

Secure the antenna with wooden sticks on the sides

If there is no connector for the antenna, use a copper plate to secure the wire to the modem

Antenna GSM with their own hands

In recent years in Russia has significantly increased the coverage area of networks of standard GSM 900.Nevertheless, the situation is far from ideal. If in the European countries the problem of unreliable reception practically is absent, but the majority of domestic users often face it. In country houses, vacation homes, etc. Д. And how it would be wonderful to go fishing, hunting, in the countryside, without losing touch with the outside world! The key to solving this problem. External directional or non-directional antennas. True, buying an antenna is not enough. It must be installed and configured correctly. Readers who are familiar with radio electronics can independently make and tune the antenna working in GSM. Today we’re going to talk about the types of antennas and how to install and configure them.

To put it simply, cell phone is a duplex radio station, which leads radio exchange on different frequencies. There are 124 frequencies in total in the GSM 900 standard. The telephone, like a base station, can operate on any frequency determined by the operator. The base station (BS) transmits and the telephone (MS) receives on frequencies 935.2. 959.8 MHz. The cell phone transmits and the base station receives on the frequencies 890.2. 914.8 MHz. The channel from BS to MS is called Down Link, from MS to BS. Up Link. Most operators use range limitation of cell phone from base station. 35 km, which is due to the peculiarities of the standard. Let’s explain that in a network of a standard configuration in one frequency channel is formed 8 time-slots (time-slots): one service, and seven. Talking. Exactly in this case, the maximum communication range on each channel is 35 km. However, GSM also provides a non-standard configuration of the cell, in which the communication range is increased by 70. 100 km (Extended Cell configuration). Unfortunately, this configuration reduces the number of talking channels to 2. The power of the base station is usually 20 to 3, thus reducing the capacity of the network. It is not profitable for the operator to use this mode in or near the city. Sometimes this mode is used on seashores to create coastal coverage. Thus, if you have a telephone standard GSM 900, do not try to establish communication by moving away from the nearest base station more than 35 km. The maximum communication range that I have achieved. 34 km. The following factors affect the range of radio communication:

Base stations usually have a capacity of 20. 30 W. The antennas are used either rod or directional. The sensitivity of the base stations is.100 dB. 115 dB. All of these parameters can of course not be changed or influenced by the user. The phone has an output power of 0.3. 2 W, sensitivity. 90. 105 dB. The sensitivity of the phone is mainly determined by the technology used to create low-noise input devices. If in the areas of confident reception the difference in sensitivity and power between models is almost imperceptible, in the area of uncertain reception it can become critical. Often the handset indicates the signal strength from base station 1. 2 cc (according to scale) and can’t establish connection: not enough power. And although ETSI standardization regulates the standard output power for each class of phone, the actual value can vary slightly. SAGEM, Alcatel, Motorola handsets have good sensitivity. All older phones, especially Motorola, pass muster in terms of power. All phase 2 phones have about the same power. As for the topography, waves travel better on flat terrain and along the river. The higher you are (within reasonable limits), the better the signal. The forest sometimes “dampens” the waves more than urban areas.

So you’re out of town and you want to make sure you’re connected. Climb to the roof, attic, or highest point near your home or the location you want. If your phone has network coverage but is at a limit (or unstable), you have a good chance of getting it right by using an external antenna. If the distance to the station is less than 30 km and you can’t get a signal, you should also try to use an antenna. In the last case try to agree with the seller about the return of the antenna if the experiment fails.

If you get a signal, even if it is very weak, dial any city number. To check. If the conversation is normal and the interlocutor does not complain about the loss of pieces of your speech, it means that the energy of both lines (UL and DL) is balanced and you can use a standard antenna, tuned to a medium frequency between the transmit and receive frequencies. If the interlocutor disappears from time to time, it is necessary to “strengthen” the downward direction from the base station to your phone. It may be worth looking for a phone with better sensitivity. But if you can not hear well, you should amplify the direction from your phone to the base station. Already at this stage it is clear that when selecting the type of antenna and its parameters it is desirable to take into account the data operator and reception conditions.

In areas of uncertain reception is often observed interference (interference) between channels with the same and adjacent frequencies. Unfortunately, the frequency resource allocated to GSM 900 operators in Russia is limited, so in the area of weak reception are often “visible” frequencies from different base stations with the same or neighboring signal strength. Such frequencies create mutual interferences interfering with communication, and at certain signal levels communication becomes impossible at all. If the phone screen registers a strong signal from the base station, and you can’t connect, or you can, but the speech keeps disappearing, it means that you’ve encountered “strangers”. “Make” the phone to choose another frequency is not always possible, but a special function of Nokia phones. Netmonitor. It allows to do.

I encountered a similar problem in the country house, which is separated from the big city by quite an open space. The phone received the neighboring frequency channels at 70dB, 73dB and 72dB, but the quality of connection left much to be desired. The only thing that saved me was the forced choice of another frequency channel with a lower level. 80 dB. However, with limited frequency resource, even frequency rescheduling of the network is not always helpful. Nevertheless, if your phone has no Netmonitor, it is possible to use the external directional antenna with a good directivity diagram. You only have to make the right choice.

As said before, it is the external antennas that allow me to increase the range and quality of the connection. External pin and log-periodic antennas, as well as wave channel type antennas, are mostly used for telephones. Let’s repeat that in Western Europe there are no areas of uncertain reception. Therefore the directed aerials for terminals GSM 900 practically are not issued. If the manufacturer and offers a directional brand antenna GSM 900, it is usually designed to work with repeaters (repeaters) operators.

Mirror antenna. Reflector

One more, very good way to forget about how to strengthen the signal, is to use the reflector. The antenna of the modem itself serves as an emitter. The size of the reflector is approximately 150×200 mm (great accuracy is not needed here), and the modem must be a quarter of a wave away from the reflector. Here it is necessary to experiment a little, but in any case this distance lies within the limits of 30-40 mm.

The reflector is made of tin, thin aluminum, even meat foil glued to cardboard, with a bend roughly shaped like a paraboloid, so that the Focus is at the point where the modem is located. This antenna gives a gain of about 10-12 dB (actually 9-10). By the way, this kopeck self-made, its full analogue, well, unless nicely made, sold in stores for 900-1000!

The disadvantage in case of such antenna will be impossibility to expose it in the street. The modem and SIM-card are not calculated on rains and frosts. The best place to install it is near the window, in the direction of the cell tower. The signal strength can be estimated by the “sticks” on the signal indicator in the software to work with the modem. However, it is better to evaluate the quality of communication by the reception and transmission speed on the speedtest website.You can try to tilt the modem with the reflector at an angle of about 45 degrees and look at the test again to better adjust to the polarization of the reception place. Such tests need to make about three or more to assess the antenna’s ability to amplify the signal.

GSM. Homemade amplifier with antenna

You can try to create your own special mechanism to amplify the cellular signal at home. To increase the cell phone signal you will need: a piece of iron wire (35-40 cm), 2 connector block, a small bolt and nut, 10 m of coaxial cable, a piece of water pipe and a plastic container.

To make the antenna, line the wire with pliers and gently bend it 90 degrees in the center. Measure 9 cm on both sides from the center and bend the wire inward at a 90 degree angle. The edges of the wire should also be bent inward by 90 degrees. The distance from the last bend should be 8 cm.

Install the connector block on the ends of the wire and secure it with a screwdriver.

Saw one side of the pipe in half, and make a hole in the center on the other side. The hole should be of such a size that the bolt can go. Insert the bolt into the hole, fix the antenna on top and secure it with the nut.

Next you need to connect the coaxial cable. To do this, strip the end of the cable and separate the inner and outer wires. Connect the inner wire to one side of the small block and the outer wire to the other.

Place the homemade GSM antenna on top of the TV antenna in the same direction and pull the cable into the house.

Strip the other end of the coaxial cable and divide the wires inside it again. At this time you need to cut the outer wires, as you will not need them. Take a piece of plastic and cut it any shape you want. Make a small hole on one side and pull the inner wire of the coaxial cable through it. You can reinforce this construction with tape. Now you can put the modem on this piece of plastic or attach it to the back of your phone and your signal will increase!

You may notice that it is possible to build such a GSM / 3G / 4g signal amplifier with your own home. However, it requires certain materials, minimal skills and, importantly, enough free time.

What will be necessary for manufacturing of the aerial

Efficiency of a homemade antenna for a smartphone

Everyone will be able to construct a self-made aerial for the smartphone. And still its efficiency can be insignificant if it is not adjusted correctly. The normally adjusted for reception of a signal of the cellular operator the aerial in times will improve quality of communication. The sensitivity of the built-in antenna in the gadget may be insufficient in bad weather conditions, while an additional antenna is able to increase it many times. It is necessary to consider, that efficiency of application of the homemade aerial for a cellular telephone depends on a choice of a variation of its design:

The wave antenna is a traverse with reflectors at right angles to its plane. This type allows to improve considerably quality of a received signal, but demands accurate pointing to the station.

Antenna for cellular phones with their own hands

In order to assemble an antenna capable of improving the quality of signal reception by cell phone, you will need the following materials and elements:

• Plastic or plywood, and a piece of foil (or foilized textolite);
• 10 meters of coaxial cable;
• 30 centimeters of wire;
• Fasteners;
• Connecting elements;
• Duct tape.

Assembling such an antenna begins by giving a piece of metal wire a suitable shape. Usually it is bent in a rhombus shape. The ends of the resulting wire loop should be bent inward and a coaxial cable should be attached to them. The other end of the cable product should be attached to a piece (with a side of approximately 40-100 millimeters) of foilized textolite. If the latter is not available, it is possible to glue a rectangle of foil on a piece of plastic or plywood of an appropriate size.

Example of 4G 3G signal amplifier

Now it remains only to install the diamond-shaped contour of our antenna on the roof or on the pole (the main thing. Upwards) and check the quality of the resulting gain. To do this, hold your phone to the foil plate and observe the level of the signal it receives.

Important! Such an antenna can be used in the ambient temperature range from.40 to 50 degrees Celsius.

The above described scheme of the organization of the system to improve the quality of mobile data is the most primitive and general. If necessary, you can replace the foil element on one end of the coaxial cable with a jack of a suitable design for your phone, or with a splitter. Thanks to the latter you will be able to improve the quality characteristics of the network in several points. Accordingly, the necessary cables will depart from the splitter, the ends of which can also be fitted with suitable connectors for connecting phones.

However, you should keep in mind that the more branches in such a system, as well as the longer your cable route will be, the less effective the assembled amplifier will be in its work.

Now you know enough about how to strengthen the cellular signal on the phone to carry out these activities not only through the purchase of factory products, but also with their own hands.

Devices for improving the quality of received mobile data will allow you to stay in touch with the outside world, being practically in any corner of the globe. In addition to the basic functions, they will reduce the level of radiation from mobile devices, eliminate unwanted interference, as well as increase the time of battery discharge, as well as its service life.