Take a mesh colander. It is best to use Asian "scoop" type cookware (like a wok but with a mesh) that is used for frying. Its shape is perfect for our purposes, and it also comes with a wooden handle!

• You can also use a sieve, a steamer, a pot lid and a lampshade, provided they are hemispherical and made of metal. Any parabolic mesh piece of metal will do - the larger the better the signal, although this can make installation difficult.
• For larger options, old parabolic television antennas or a mesh umbrella frame. Although they will give more signal gain, there may be installation and drag issues, so 300mm seems to be the most practical.
• Flexible leg from table lamp allows you to accurately position and point your antenna.

We assemble the system. Use wire, tape, or hot melt adhesive to attach the Wi-Fi adapter and USB extension cable to the plate.

• The adapter must be mounted in the center of the dish's "hot spot" - radio signals enter the dish and are reflected back to the center a few fingers above the surface of the dish.
• The best location for the adapter can be determined with a simple experiment. One method is to cover the plate with aluminum foil to determine how sunlight is reflected in it - the most illuminated point is the point of focus of the plate.
• You may need a small bar to secure the adapter in the required position.
• Alternative ways to secure: Use string tied around the front of the plate in a spider web, scraped plastic garden hose fittings, or even chopsticks!

Antenna connection. Plug one end of the USB extension cable (male) into your computer, and into network settings set it up as a Wi-Fi adapter.

If you want to assemble a long-range WiFi antenna, then you should know about some of its features.

First and foremost, large antennas of 15 or 20 dBi (isotropic decibels) are power-limiting and don't need to be made even more powerful.

Here is a clear illustration of how, as the antenna power in dBi increases, its coverage area decreases.

So it turns out that with an increase in the distance of the antenna, the area of ​​\u200b\u200bits coverage decreases significantly. At home, you will have to constantly catch a narrow band of signal action when too powerful WiFi emitter. Get up from the couch or lie down on the floor, and the connection will immediately disappear.

That's why home routers have conventional 2dBi radiating antennas so they're most effective over short distances.

directional

Antennas at 9 dBi work only in a given direction (directional action) - they are useless in a room, they are better used for long-distance communication, in the yard, in the garage next to the house. A directional antenna will need to be adjusted during installation to transmit a clear signal in the desired direction.

Now to the question of the carrier frequency. Which antenna will work better at long range, at 2.4 or 5 GHz?

Now there are new routers operating at double the frequency of 5 GHz. Such routers are still new, they are good for high-speed data transfer. But the 5 GHz signal is not very good for long distances, as it decays faster than at 2.4 GHz.

Therefore, older 2.4 GHz routers will perform better in long-range mode than newer, faster 5 GHz routers.

Drawing of a double homemade biquadrate

The first samples of home-made WiFi signal distributors appeared back in 2005.

The best of these designs are bi-square, providing amplification up to 11-12 dBi and double bi-square, having several best result at 14 dBi.

According to user experience, the bi-square design is more suitable as a multifunctional radiator. Indeed, the advantage of this antenna is that with the inevitable compression of the radiation field, the signal opening angle remains wide enough to cover the entire area of ​​\u200b\u200bthe apartment with proper installation.

All possible versions of the biquad antenna are easy to implement.

Required Parts

• Metal reflector - a piece of foil textolite 123x123 mm, foil sheet, CD, DVD CD, aluminum lid from a tea can.
• Copper wire with a section of 2.5 mm.kv.
• A piece of coaxial cable, preferably with a wave impedance of 50 ohms.
• Plastic tubes - can be cut from a ballpoint pen, felt-tip pen, marker.
• A little hot glue.
• N-type connector - useful for convenient connection of the antenna.

For the 2.4 GHz frequency on which you plan to use the transmitter, ideal sizes bi-square will be 30.5 mm. But still we do not satellite dish, therefore, some deviations in the dimensions of the active element -30–31 mm are permissible.

The question of the thickness of the wire also needs to be taken carefully. Given the selected frequency of 2.4 GHz, the copper core must be found exactly 1.8 mm thick (with a cross section of 2.5 mm2).

From the edge of the wire we measure the distance of 29 mm to the bend.

We make the next bend, controlling the outer size of 30-31 mm.

We make the following bends inward at a distance of 29 mm.

Checking the most important parameter the finished biquadrate has -31 mm along the midline.

We solder the places for the future fastening of the coaxial cable leads.

Reflector

The main task of the iron screen behind the emitter is to reflect electromagnetic waves. Correctly reflected waves will superimpose their amplitudes on the vibrations just released by the active element. The resulting amplifying interference will make it possible to propagate electromagnetic waves from the antenna as far as possible.

To achieve useful interference, it is necessary to place the emitter at a distance of a multiple of a quarter of the wavelength from the reflector.

Distance from emitter to reflector for antennas biquadrate and double biquadrate we find as lambda / 10 - determined by the features of this design / 4.

Lambda is the wavelength equal to the speed of light in m/s divided by the frequency in Hz.

Wavelength at a frequency of 2.4 GHz - 0.125 m.

By multiplying the calculated value five times, we get optimal distance - 15.625 mm.

Reflector size affects the antenna gain in dBi. Optimal dimensions for a biquad screen - 123x123 mm or more, only in this case it is possible to achieve an amplification of 12 dBi.

The sizes of CDs and DVDs are clearly not enough for complete reflection, so biquad antennas built on them have a gain of only 8 dBi.

Below is an example of using a tea can lid as a reflector. The size of such a screen is also not enough, the antenna gain is less than expected.

Reflector shape should only be flat. Try also to find the plates as smooth as possible. Bends, scratches on the screen lead to the scattering of high-frequency waves, due to the violation of reflection in a given direction.

In the above example, the sides on the cover are clearly superfluous - they reduce the signal opening angle and create dissipated interference.

Once the reflector plate is ready, you have two ways to assemble the emitter on it.

1. Install copper tube using soldering.

To fix the double biquadrate, it was necessary to additionally make two small ballpoint pen stands.

1. Fix everything on a plastic tube using hot glue.

We take a plastic box for discs for 25 pieces.

We cut off the central pin, leaving 18 mm in height.

We cut four slots in the plastic pin with a needle file or file.

We trim the slots equally in depth

We install a home-made frame on the spindle, check that its edges are at the same height from the bottom of the box - about 16 mm.

Solder the cable leads to the emitter frame.

Taking a glue gun, we fix the CD at the bottom of the box with plastic.

We continue to work with a glue gun, fix the emitter frame on the spindle.

On the back of the box, we fix the cable with hot glue.

Connecting to a router

Anyone with experience can easily solder to the pads on the circuit board inside the router.

Otherwise, be careful, thin tracks may come off printed circuit board during long-term heating with a soldering iron.

You can connect to an already soldered piece of native antenna cable via an SMA connector. Buying any other N-type RF connector at your local electronics retailer should be no problem.

Antenna Tests

Tests have shown that an ideal bi-square gives a gain of about 11-12 dBi, which is up to 4 km of a directional signal.

The antenna from the CD gives 8 dBi, because it turns out to catch a WiFi signal at a distance of 2 km.

Double bi-square delivers 14dBi - a little over 6km.

The opening angle of antennas with a square radiator is about 60 degrees, which is quite enough for the courtyard of a private house.

About the range of WiFi antennas

From a native 2 dBi router antenna, a 2.4 GHz, 802.11n signal can extend up to 400 meters within line of sight. Signals of 2.4 GHz, old standards 802.11b, 802.11g propagate worse, having half the range compared to 802.11n.

Considering the WiFi antenna as an isotropic radiator - an ideal source that propagates electromagnetic energy evenly in all directions, you can use the logarithmic formula for converting dBi into power gain.

Isotropic decibel (dBi) - antenna gain, defined as ten times the decimal algorithm of the ratio of the amplified electromagnetic signal to its original value.

AdBi = 10lg(A1/A0)

Converting dBi antennas into power gains.

Judging by the table, it is easy to conclude that a directional WiFi transmitter with a maximum allowable power of 20 dBi can propagate the signal to a distance of 25 km in the absence of obstacles.

Short review
This wireless adapter Can be operated from laptops, laptops and desktop computers as well. just plug in and enjoy the Internet.

Peculiarities:
802.11n/g/b 300M Wireless WiFi USB 2.0 Adapter (Realtek 8191 Chipset).
Conforms to IEEE 802.11n (draft), IEEE 802.11g, IEEE 802.11b.
Provides USB 2.0/1.1 high speed interface.
Transfer rate up to 300Mbps.
Supports Ad-Hoc mode, WLAN network infrastructure, wireless roaming.
Support for Windows 2000, XP 32/64-bit, Vista 32/64-bit, Linux, MAC OS x.
With external antenna.
Simple configuration and easy to use.
It can be developed from laptops, laptops and desktop computers.

Specifications:
Wireless standards: IEEE 802.11n (draft), IEEE 802.11g, IEEE 802.11b standards.
Interface: high speed USB 2.0/1.1
Transfer rate:
802.11n up to 300M (downlink) and 150M (uplink);
802.11G 54/48/36/24/18/12/9/6Mbps auto standby;
802.11b 11/5. 5/2/1 Mbps auto backup.
Frequency Range: 2.4 GHz ISM.
Chipset: Realtek 8191
Frequency range: 2412-2462 MHz (North America); 2412-2472 MHz (Europe); 2412-2484 MHz (Japan).
Output power: 13-17dBm.
Radio channel: 1-14 channels.
Range: Up to 3 times farther range than 802.11g.
Roaming: Full mobility and seamless roaming from cell to cell.
Modulations: 11n BPSK QPSK 16QAM 64QAM OFDM; 11g BPSK QPSK 16QAM 64QAM OFDM; 11b DQPSK DBPSK DSSS CCK.
Data security: 64/128-bit WPA, WPA-PSK, WPA2-PSK, TKIP/AES Wep encryption.
Media Access Control: CSMA/CA with ACK.
LED indicators: link/active (green).
Operating system: Windows 2000, XP 32/64-bit, Vista 32/64-bit, Linux, MAC OS x.

We will need:
CD box.
Copper wire with a diameter of 2.5-3 mm.
Compact disc (plays the role of a reflector). You can also cut a circle out of copper yourself.
Antenna cable.

We assemble the antenna itself, observing the dimensions.

We clean the cable in such a way that the screen braid is longer than the central wire.
We leave about 5 mm of insulated wire from the central cable.

With an awl or a sewing needle in the center of the central braid (next to the wire), we make a puncture into it, the central wire of the adapter antenna will enter.

Unscrew the antenna from the adapter.
From the old marker, I cut off a small piece of the tube (this will be an adapter and a latch between the adapter and the cable).