Homemade directional antenna for wifi adapter. Three external antennas for Wi-Fi

25.05.2019 news

With the kind permission of Vladimir (VBM), we reprint his description of the design of the FA-20 sector panel antenna, which, despite its simplicity, has proven itself to be high-performance and reliable.

1. Introduction

The original description of the author is located at http://sterr.narod.ru/wifi/fa20.htm. Description from Volodya - http://vbm.lan23.ru/wifi/fa20.html. You can find a lot of positive feedback about this design on the net, but it is noted that manufacturing accuracy is very important, especially for vibrators and mounting holes in the reflector. Also of great importance is the observance of the distance between the reflector and the vibrators. Be sure to adhere to the specified dimensions, this will maximize the efficiency of the antenna.

2. Construction

The antenna consists of four structural elements: a reflector (1), two types of vibrators (2, 3) and a connecting bus (4), which serves to connect the vibrators:

3. Materials

To assemble the antenna, we need:

One-sided foil textolite (for reflector)
Double-sided foil textolite (for vibrators)
Strip of brass or copper foil (for bus)
Aluminum corner 25×25 mm
Rivets
F connector

4. Manufacturing

First of all, you need to make a "trough" of the reflector. To do this, according to the drawing, we cut out a rectangle of foil textolite 490 × 222 mm for the bottom, mark it (it is best to core from the side of the foil) and drill holes with a diameter of 2.5 mm for the racks for vibrators, tin them. After that, we make the sides of the appropriate size from an aluminum corner 25 × 25 mm, and fasten them with rivets on the reverse side of the reflector:

blanks

For accurate marking, it is best to use a caliper.

When attaching the corners with rivets, also fasten the edges of the corners

After assembling the “trough” of the reflector, it can be slightly strengthened by gluing the corners on the reverse side with mounting tape, and gluing the vertical seams with two-component epoxy glue:

Structural reinforcement

Volodya came up with an original technology for manufacturing vibrators from fiberglass laminated on both sides. The advantage of this method is that two absolutely identical vibrators are obtained from one workpiece.

First, a rectangular blank of the desired size is cut out of textolite:

Preparation for the manufacture of vibrators

Cut out rectangles with metal scissors
We delaminate fiberglass, we try to delaminate halves of the same thickness
We make cuts along the red lines of the rectangles with 2 ordinary household scissors
We take a broken blade of a hacksaw for metal and cut along the green lines of the rectangles 2
With fine sandpaper, carefully clean the ends of the resulting vibrators

Ready vibrators

As a result, we get two vibrators of identical sizes. Care must be taken to ensure that the non-foil side of the vibrator is smooth, this may require removing a layer of fiberglass. After that, we drill and tin holes with a diameter of 2.5 mm for the racks.

After manufacturing the vibrators, it is necessary to make a tire (4) from brass or copper foil, with the help of which we will later connect the “tails” of the vibrators.

All elements of the future antenna are ready, you can start assembling. To do this, you need to find a remote gasket under the vibrator. Select its thickness so that the total thickness of the textolite and the spacer gives a distance of 6 mm between the reflector and the vibrator foil.

To install vibrators, it is best to use a smooth thick copper wire with a diameter of about 2 mm. We cut it into small pieces, solder them in the holes of the "trough". Then, placing a spacer next to the stand, solder one edge of the vibrator, then similarly - the other, after moving the spacer. We bite off the extra parts of the racks. When installing, narrow vibrators are placed at the edges, wider ones in the center.

Antenna assembly

After installing the vibrators, we fix the connector on the “trough” and connect the “tails” of the vibrators with the help of a tire, carefully soldering them, then solder the central vein of the connector to the tire.

5. Installation

The easiest way to attach the antenna to the bar is to drill holes in the "trough" between the central vibrators, and screw it on with screws or screws. If you plan to fix the antenna on the pipe, it is better to rivet an aluminum corner about 30 cm long to the antenna on the back of the reflector, then attach the corner to the mast using clamps or ties.

Thanks to the forum members for the information provided.

In the modern world, a wireless network is widespread, to which almost every home is connected. It happens that in a building of 2-3 floors, the signal in some rooms is weak or completely absent. One of the reasons for this situation is an incorrectly selected antenna for a device such as a router. At the moment there is a wide range of these devices. An antenna for a router with your own hands can also be made, but this requires certain skills and knowledge, which we will consider below and get acquainted with how the system itself works.

How does an antenna amplify a signal?

The antenna is a passive amplifier, that is, it does not use external energy to amplify the signal. Amplification of the signal occurs due to the fact that the propagation of radio waves in space is redistributed. A classic rod-shaped antenna is capable of emitting a circular signal that has approximately the same power in all directions. The further away from the transmitter, the worse the signal becomes. If necessary, redistribution of the antenna radiation is available, which allows you to amplify the signal in a particular direction, weakening it in others.

There are many software methods that allow you to enhance the signal transmission of a wi fi antenna. The methods are as follows:

Use WPA/WPA 2 protocol;
Reduce the number of devices requiring the use of MAC addressing;
Hide the name of the wireless network.

The legacy security protocol (WPA) makes the network not only less secure, but also slower. You need to change the protocol to WPA 2, which is done in the router settings section. It is also possible to significantly increase the power of the device by limiting the number of supporting devices. As for the MAC addresses themselves, these are identifiers. It is not recommended to leave the network open, since its quality directly depends on the number of connected devices (and if Wi-Fi is available, then everyone will use it). To hide the name, uncheck the "enable SSID broadcast" checkbox in the setup menu).

Types of WiFi antennas

WiFi is a technology that is only capable of normal functionality with "line of sight". The wireless signal is easily lost among obstacles such as cabinets, walls, mirrors, and so on. Therefore, if you want the network to work stably, you need to carefully consider the issue of choosing an antenna for a wi fi router.

There are two types of WiFi antenna: directional and omnidirectional (internal and external). Modern wireless networks are usually based on omnidirectional antennas. Their task is to evenly distribute the signal over the radius of action. Often, such devices have the form of a conventional pin that propagates a signal in a plane perpendicular to its axis.

Important! The omnidirectional Wi-Fi antenna is installed only in a vertical position. This provides the maximum coverage of the wireless network.

In some cases, coverage of a large area is required, such as in a manufacturing facility. This is easily achieved with an outdoor omnidirectional wifi antenna with a gain of 8 dB installed on the central building. The transmission radius of a powerful device is 600 meters.

With the help of a directional wifi antenna, a point-to-point network is organized. This device does an excellent job if you need to connect to only one access point or one computer.

Let's consider an example of work. Such an antenna is able to "pierce" the walls in the room. A panel type of device is often used, which is a flat rectangle that transmits radio waves in one direction. As for the gain, it sometimes reaches 6 dB. If it is necessary to transmit a signal, for example, to a neighboring house, it is recommended to install an external antenna having a cylindrical shape. It is mounted in a horizontal position, as it directionally transmits a signal in the direction where the receiver is located. In this case, the gain reaches 18 dB.

There are also parabolic antennas that transmit a wireless network signal between similar devices over a distance of several kilometers. Such devices are relevant if signal transmission is required over a distance of more than 100 meters. The gain of parabolic antennas reaches 24 dB.

How to install an external antenna for a router

The first thing to figure out is where the router should be. After all, if there are obstacles in its path, then the reception signal is weakened. Here it should be understood that each obstacle in its own way worsens the quality of reception. For example, a concrete wall is much “thicker” for a router than a wooden one.

In a word, for effective signal propagation, it is necessary to install the router in such a way that there are as few obstacles as possible in its path. The most suitable place is an elevation in the center of an apartment or house (an omnidirectional Wi-Fi antenna). If directional is used, then it is logical to direct it to the area where stable and high-speed Internet is required most often. The same goes for outdoor devices. It is recommended to follow the updates of the router - firmware. It is better that the latter is used, correcting certain disadvantages of the work. Also, experts advise not to place the adapter near windows, mirrors and steel structures.

We make an antenna with our own hands

There are many different schemes on the Internet that allow you to make a directional antenna. One of the more popular examples is the 12 dB double bi-square. To assemble such a device, a copper wire (diameter - 2-3 mm) 30 cm long is useful. The reflector here is a plate of foil getinaks - pressed paper impregnated with an adhesive and covered with copper foil. It is not always possible to find such a metal, so it is replaced by any other, up to the cover of the system unit or an ordinary beer can.

First, a double figure-eight of wire is bent (squares should have sides of 30 mm). To do this, the wire is marked into 8 equal parts and bent in the marked places by 90 degrees with pliers. As a result, a kind of do-it-yourself antenna is obtained, which looks like a figure eight.

Next, a reflector is cut out of the getinax plate. Two holes are drilled in its center - one for the antenna itself, the second for the wire. Between the copper figure eight and the plate, a distance of at least 15 mm should be observed.

Next, you will have to work with the router itself, or rather, its small wi fi antenna. The wire must be brought out, for which a small hole is drilled in the body of the device. A central wire is soldered to a self-made antenna in the form of a figure eight, and a winding is soldered to the leg.

If desired, you can make an ultra-long wi-fi antenna. To do this, you need to find a foil sheet of getinax and fiberglass. It is important that the material is of good quality, of sufficient thickness and size. You will also need to use self-adhesive vinyl stencils with mounting film, necessary to protect the mentioned sheets from etching.

The rear wall-reflector is made of any flat sheets of metal. It can even be foil, as long as it is flat and even. First, you should mark the textolite and cut it with a grinder into two parts - 450 by 350 mm. Before proceeding with etching, the sheet must be cleaned with a fine-grained sandpaper. It is important to keep a distance of 9 mm between the getinax reflector and the board, which is achieved by using even plastic. Next, the resulting parts are glued together. A hole is left in the soft plastic, which will later allow you to solder the wire. Wires and connectors are available from radio markets. As for the choice of connector, here you need to rely on the antenna of the router.

The result is a do-it-yourself ultra-long antenna. From the access point at a distance of 1 km, the power of the device reaches 80 dB.

Amplifying the signal is quite simple, for this it is important to know certain subtleties and correctly assemble. So, high-quality communication is achieved subject to the following rules:

In order for the signal to be evenly distributed throughout the room, the router should be installed as close to the center of the room as possible;
The equipment should not be installed on the floor or near radiators, which will significantly impair communication transmission;
The standard equipment of modern routers is usually omnidirectional, so it is recommended to purchase more powerful antennas;
There are many methods that allow you to improve the signal with your own hands. The simplest is foil glued to the cardboard and installed in the right direction;
Replacing the adapter allows you to amplify the signal;
If you install a repeater, this device will significantly increase the signal transmission radius.

At the moment, almost everyone uses Wi-Fi, but not everyone likes the speed of the Internet. Fortunately, now there are many ways to improve the quality of the transmission, where the choice of a specific one depends on various parameters. It is also recommended to clean the registry from time to time, clearing it of unnecessary information.

In the modern world, a wireless network is widely used - wifi. For its operation, special equipment is installed - routers equipped with antennas. The latter are of several types, where each has its own characteristics, advantages and disadvantages. Asking the question “how to make wifi faster”, you need to understand that there are different ways, both free and requiring investments.

Video

Now in amateur radio practice, antennas for amplifying 3G, 4G, Wi-Fi signals of the "Bikvadrat" type are very common.

Such an antenna has a directional action, which may not always be an advantage, but even a disadvantage. An example is this: you need to amplify the signal of your router so that you can catch it in any part of your house. If you use a directional antenna, then the signal will most likely be well available only in the field of action of this antenna. Surely this will be only one room where she will be directed. It is good to use such an antenna only for long-distance communication, provided that you know where to point it.
To amplify your WI-FI signal in all directions, an antenna is suitable, which I will show you. It is close to the whip antenna in its directivity characteristics, with the exception of greater sensitivity.
By structure, this is actually the same bi-square, only twice directed in opposite directions. Plus, this antenna is many times simpler than the classic biquad, since it has neither a rack nor a reflector.

How to calculate the antenna?

Just please don't be scared, fifth grade math. We only need to calculate one arm, since the antenna is square. But first you need to find out at what frequency we will make the antenna. Personally, in the example I will do under WI-FI. It is known that the WI-FI frequency is approximately 2.4 GHz or 2400 MHz (there is also an even more modern Wi-Fi - 5500 MHz). If you do under 3G - 2100 MHz, and 4G (YOTA) - 2600 MHz.
We take the speed of propagation of radio waves (300,000 km / s) and divide by the desired frequency (2400 MHz) in kilohertz.
300.000/2.400.000 = 0.125 m
This is the wavelength we got. Now divide by four and get the length of the arm of the square.
0.125 / 4 will approximately turn out 0.0315 m. Convert to millimeters for convenience and get 31.5 mm.

Making a simple do-it-yourself Wi-Fi antenna

Brem thick wire 2-3 mm thick. And a template cut from a piece of aluminum. You can of course do without it, but it's easier with it.

We bend two loops from one wire and two from the other. The gap should be between the squares.

Then, with masking tape, I temporarily fix the squares crosswise to make it easier to solder. And I solder the middle from above so that the structure becomes rigid.

Now you need to take a thick piece of cable with a connector (you can take it from the same whip antenna).

Insert inside the antenna and solder. The middle wire to the top, and the lower shoulders of the squares to the common one.

The antenna is ready. To finish, you can fill the solder joint with hot glue and paint.

Antenna testing

Compare the signal strength with the whip antenna that originally came with the router.

Whip Antenna:

Now in comparison. The first pin, and then our omnidirectional bi-square.

It can be seen that our antenna receives and amplifies the signal by 30% better. Here is the result of your work.
A good signal level is a guarantee of high Internet speed, which means a guarantee of stable operation. 30 percent is a very high figure, given that there was no need to change anything drastically.
Make your own simple antenna for 3G, 4G or Wi-Fi and no longer suffer from an unstable and weak signal.

Good afternoon, dear readers of the blog site Most recently, I talked about the possibility of increasing the coverage area by installing . However, not everyone likes this situation, and many simply do not want to give extra money. That is why I decided to describe what a reinforced wifi antenna for a router is with my own hands.

The need to increase the coverage area or achieve a more stable signal comes precisely at the moment when the user simply cannot connect to a remote part of his apartment or wirelessly several times. The most affordable way to solve this problem is to move the wireless router closer to the receiver, but we are not looking for easy ways and we will make an amplified wifi antenna for the router with our own hands.

Unfortunately, this method is only suitable for models with external antennas.

There are several ways in my arsenal to make an improved antenna for a wifi router, but since my article is aimed at inexperienced users, I will try to talk in detail about three options for homemade wifi amplifiers.

Reinforced wifi antenna from the CD box

No matter how ridiculous it may sound, but this option for making an antenna for a router with your own hands really gives a pretty good result. For manufacturing we need:

Box for discs for 25 pieces
Waste CD
Copper wire, 30 centimeters, with a cross section of 2 sq / mm (more is possible, but do not overdo it with thickness)
Coaxial cable for connection
Tools (soldering iron, pliers, glue and file)
Additional SMA connector

Open the box and cut off the guide at a distance of about 20 mm

Then, using a file, we make recesses in the form of a cross, for the subsequent installation of a rhombus.

Thanks to the pliers, we create a double rhombus from the copper wire prepared in advance. The length of each side of a single diamond should not exceed three centimeters. The resulting product can be seen in the figure below.

The ends of the wire should converge in the middle.

At the junction of the ends, we solder the wire and the ends themselves, respectively.

The next step is to push the coaxial cable through the hole in the guide in the box and use the adhesive to fix the resulting rhombus in the grooves of the guide.

For better fixation, I advise you to fix all freely moving parts with glue.

We close the resulting design of the amplified antenna of the wireless router with a lid and use the SMA connector to connect it to the router itself.

On this, our wifi antenna for the router is ready. When I personally decided to test the result, I was very pleasantly surprised by the signal strength in remote areas.

The disk box can always be replaced with sheet metal, and a soldered metal tube can be used instead of a plastic guide. There are a lot of opportunities for improvement.

Do-it-yourself reinforced antenna for a router from a tin can

From the name you can already understand that this method is primitive to disgrace and it is not necessary to spend money on the purchase of additional materials.

In the store, it is enough to buy a can of soda (or beer) and after it is empty, you can start making a home-made wifi amplifier for the router.

First of all, it is worth rinsing and drying it to get rid of the remnants of the contents. Then, using scissors, we pierce the jar in the lower part, next to the bend turning into the bottom, and cut it off. Then, along the entire length, we make an incision until the bend passes into the upper part. After that, along the circumference on both sides of the longitudinal section, almost to the very end, we cut off the cover, but at the same time leaving a small area for the stability of our screen. It will be clearer if you look at the figure below.

For greater rigidity of our design, you can not cut off the bottom of the can, but do the same as we did with the lid, which will not allow the screen to bend arbitrarily.

The next step is to mount the antenna. We put our design on the antenna, and for better fixation we take plasticine, which will not allow all this goodness to move in space.

If your router has not one, but two transmitters, then such an amplifier must be made for each, which will allow you to send a more powerful signal in several directions at the same time.

At first glance, such a device looks very elementary and unreliable, but the amplification effect makes it clear that even a simple design can give excellent results.

Unfortunately the two methods above are for directional signal improvements. Such a scheme is suitable for those users who have installed a wireless router in the corner of the room and there is no need to “distribute wifi” to neighbors.

Homemade reinforcing nozzle on the router

Another fairly simple way to strengthen the Wi-Fi signal with your own hands is to use the so-called nozzle. The principle of manufacture is simple to disgrace. You should have at hand a wire with a cross section of 1.5 - 2.5 mm, a piece of cardboard, pliers and scissors.

First of all, we cut several pieces of wire of different lengths from the wire (starting with a smaller one and gradually increasing by 4 mm.). The number of such pieces will depend on which wifi antenna you want to get.

We cut out a piece of cardboard of such a length and width that it does not bend under the weight of the wire. Next, we attach the wire to the cardboard by piercing it in equal areas.

Using scissors, cut out a hole for mounting. The appearance of the resulting structure is very similar to .

Naturally, if your router has several transmitters, then we make such a nozzle for each of them.

This design will really help to increase the coverage area and enhance signal transmission.

All the described methods for making an antenna for a router with your own hands are quite simple and do not require additional skills. However, if any questions arise during the work or a proposal appears to supplement this article, then do not hesitate to leave them in the comments.

To better consolidate the material read, I suggest watching the corresponding video.

This equipment is a wireless network signal receiver. Many people want to get more powerful performance from this device, but you should not do unjustified actions with devices with a power of 15-20 dBi. Their difference is the maximum area allowed for wide coverage. With the amplification of such an antenna, the range will increase, the coverage area of \u200b\u200bthe wireless connection will decrease.

This situation can become a serious obstacle to the comfortable use of a connection to the global network. The wave propagation area will be so narrow that the signal receiver will need to be kept at a certain point without the ability to move.

Of course, if you can’t transfer to the sofa with your phone or go to the kitchen with a tablet, then making a wi-fi antenna at home will not justify itself. It is necessary to weigh very well the need for such manipulation.

Homemade biquad antenna

The pioneers among home-made biquad-type emitters for the propagation of a wireless signal were samples back in 2005. The best modifications of these devices were bi-square, which produced a signal with a power of up to 12 dBi, and bi-square with a value of this indicator up to 14 dBi.

If we take the versatility of the device, it is preferable to install a bi-square design. This equipment will make it possible to preserve the width of the signal opening angle in the event of the inevitable compression of the radiation field.

If this device is correctly positioned indoors, it is possible to ensure reception of a stable signal throughout the territory. It is easy to implement any of the existing versions of this type of instrument.

Details for making a biquad radiator:

For a reflector, a foil textolite measuring 12.3x12.3 cm is useful;
Copper wire with a cross section of 2.5 square meters. mm;
Coaxial cable with an indicator of BC 50 Ohm;
Connector with N-type output for connecting the antenna itself.

In general, the device will look like squares connected at the corners with diagonals located on the same straight line. Looking at the photo of the wi-fi antenna, you can see a bi-square emitter and a grounded reflector. The device must be connected to the cable with the upper part, and the ground must be connected with the lower part.

The reflector is a piece of highly conductive material. Aluminum, steel or tin can do this perfectly. In some cases, it is easier to use a CD.

How to make a emitter and reflector wi-fi antenna

The manufacture of the transmitter is quite simple. Having prepared all the necessary materials, you can start creating the device.

Step by step instructions on how to make a wi-fi antenna:

Step 1. Check the suitability of all materials. For the estimated frequency of the future transmitter-receiver of the wireless network, the frequency is 2.4 GHz, which requires the use of copper wire 1.8 mm thick. This corresponds to the cross section indicated in the list of materials.

Step 2. It is necessary to prepare the wire and bend it at right angles at a distance of 30.5 from each inflection point. The main thing is that the active element should look like a square figure eight.

Step 3. We measure a distance equal to 29 mm from the edge to the bend of the wire.

Step 4. We constantly control the compliance of the outer diameter of 30.5 cm and make another bend.

Step 5. We perform a couple more internal bends at a distance of 2.9 cm into the inside of the frame.

Step 6. After completing the construction of the active element, you should check the compliance with the drawing. There should be a distance of 30.5 mm along the midline.

Step 7. In places that are reserved for the subsequent attachment of a coaxial cable to them, it is necessary to make a solder.

Reflector

This piece of equipment is designed to reflect waves at the rear of the network receiver. With the correct location of the reflector, it is possible to achieve signal amplification by superimposing the amplitudes of the emitted and reflected signals. The effect of interference helps to increase the range of propagation of wireless radiation.

The achievement of this physical phenomenon can be easily calculated. The selected oscillation has a certain wavelength, and when reflected, it is necessary that the waves overlap.

The distance between the reflector and the emitter is defined as the difference of a quarter of the value determined by the design features of the transmitter from a tenth of the wave. From simple considerations, we obtain a value of a quarter wavelength.

For the selected frequency of 2.4 GHz, the wave will be 12.5 cm long. Multiplying the resulting value by 5, we get the value of the desired interval of 1.56 cm.

In order to get the maximum possible gain of 12 dBi from the device you are designing, you need to correctly size the reflector. The maximum gain will be with a 12.3x12.3 cm plate. You can also use large reflectors, but this will not give any effect, but will make the equipment more bulky and heavy.

The given scheme of the wi-fi antenna device gives a radiation power of 12 dBi, and analogues made on the basis of CDs can provide a maximum of 8 dBi signal due to a limited area.

In addition to the size and type of material for the reflector, it is necessary to choose smooth plain surfaces with good reflective properties. Waves can scatter on any defect, which leads to a partial signal loss.

The collection of the emitter on the reflector can be done by soldering a copper pipe directly to the reflector. You can also fix it with hot glue on a plastic tube. It is necessary to solder the leads to the cable to the emitter frame.

Connecting to a router

It may happen that making such a wi-fi antenna with your own hands will be more of a problem than a financial acquisition. Since the connection of self-made equipment must be carried out through penetration into the router.

For anyone who has the skills to work with network and wireless equipment, the process of soldering on the circuit board to the contact pads inside the router will not be difficult.

You should be very careful and work as quickly as possible with a soldering iron with contact tracks, since they are very thin and can immediately react to a temperature jump by breaking away from the board.

If the original cable has an SMA connector, connect the same type of antenna plug. Such an RF connector is very common equipment, so you can buy it at any specialized store.

WiFi Antenna Testing

By building a biquad antenna to the ideal dimensions, following all of the above guidelines, a signal with a range of 4 km can be achieved.

You need to understand that a lot depends on what you can make a wi-fi antenna so that the indicators are consistent with the theoretical ones. The power of such equipment can reach 12 dBi.

For antennas made from CDs or other scrap materials, a weaker signal is observed, sometimes peaking at 8 dBi. With successful crafts, the directivity and range of the emitter on a CD can reach 2 kilometers.