Which antenna to buy a modem

Communication works in linear polarization (exception - satellite espionage). Modem or cell phone, the difference is small. Consequently, the same antenna. The main thing - to know the frequency of the signal, it is essential for the geometrical dimensions of the device. As for the wave impedance is 50 ohms for any type of communication - refers to the amateur technical solutions. In fact, fit universal antenna for home, try to do similar with their own hands. Consider the antenna selection for the modem.

Modems for communication via Wi Fi

Access point - the perfect solution. And through the router from a number of providers give birth to computer network (or gateway), if the connection is not private. Connect a pair of computer admissible on WiFi, but do not forget that wireless protocols are harmful to health. The access point, set somebody on the balcony is a great solution: the power does not hurt and can be seen far away. But it is difficult to catch the signal. Here there is the complexity of the antenna:

• WiFi Neutral pin radiates in all directions, it is simply a coherent piece of wire. What to do if the device does not work. First, lengthen. Traditionally used wave vibrator. Shoulder length calculated from the C / f expression, where C - 299792458 speed of light, f - frequency in Hz and equal wavelength. For 2.4 GHz WiFi obtain 299792458/2450000000 = 12.23 cm. If the antenna to increase the 5/8 wavelength: increase power handling at the reception, the current distribution will be different. Properties described pin:

1. Characteristic impedance 49 ohms. This is good, since the communication device are calculated on a 50 Ohm, error tolerance.
2. gain relative to a half-wave dipole is equal to 6 dB, without the drawbacks, this monopole antenna is better! When compared with the anisotropic emitter orientation coefficient is 8.19. This is better than the other antennas. It is clear that the main lobe vertically compressed. Keep this in mind when determining the location of the transmitter.
   

   The basis for antenna

• The best of the antenna, it is possible to get it to do anything on their own, is considered biquadrate Kharchenko. Constructive compared with vibrators and J-antenna, resulting in received numbers speak for themselves. In the fourth power Kharchenko pronounced directional properties. It is provided as one main beam and two spaced in azimuth by 180 degrees. Both cases are appropriate in different situations. Design biquadrate already dedicated reviews. But to buy an antenna for modem of this type is almost impossible. We believe that there is no demand, because the Internet is full of reviews, how to make her own.
• Strip grating is often called patches. Buying antenna from the plant, are free to choose the properties. For example, the store roll two similar AX-2418P and AX-2415PS60, they have twice the width of the different lobe. This means the coverage area. For example, the access point is standing on the windowsill gamer, and the team lives in the neighborhood. It is necessary to measure coverage in degrees, if it turns 30, take first if the 60 - second. Strengthening of the latter will be reduced. Possible to make your own patch? We believe that dismantling the factory product, you get a copy constructive. Is it legitimate, think for yourself.
  

  A log-periodic antenna

• For modems sold wave channels, it is possible to get and log-periodic antenna, probably. Plus appears when communication over long distances. But need line of sight. Distance is measured in kilometers, if you aim the antenna. You can play online, or just to share files.

Buy pin for the antenna is not the best idea, since it is possible to make yourself a better version. Create a cable from the vibrator on the 5/8 wavelength. How to do it, it is clear from reading. Try not to take the rough figures. Inspect the equipment passport, get vkalkulyator frequency. Then fabricate an antenna for a modem through 50 ohm cable by removing a braid to said length and has attached connector.

From the above it seems that the non-directional antenna is not needed. But sometimes you have to pass in different directions. Use then J-antenna. For the product range under consideration is rarely used, and complain that hard to agree on, but a gain of 15 percent in comparison to the standard pin. Calculator J-antenna here http://allcalc.ru/node/330.

Before buying a closer look at what frequency the device is designed. For example, the above embodiments are suitable for WiFi 2,4 GHz. But found and other modems operating at 5 GHz. In this case, use can be referred to the antenna, but the results may be unpredictable. Incidentally, the company's products are available on the 5 GHz band. Watch carefully.

Antennas for 3G modems

Cell phone creators are trying secretive, but in fact are within the strip antenna. Other options simply do not. And in fact, cell phones catch almost any device. This and vibrators, and antenna Kharchenko and wave channels, and the log-periodic antenna. From television entirely different setting. You have to turn on the 90-degree axis. Fill antenna side to the director (or frame) stood vertically.

Suit and patches, but the complexity in the other - how to attach the antenna to the 3G modem. In fact, the house is allowed to use a variety of devices, and the better use of WiFi. Incidentally, both Protocol harmful to human body, since the frequency of shock absorbed by water - the main component body. If not go, the H2O molecule has a magnetic moment, gripping field. At frequencies of 2.4 GHz, resonance occurs, accompanied by an increase in speed fluctuations of the water molecules and the concomitant heat.

It is recommended to create a semblance of an access point. As for the store options, the producers changed his mind, and now you can take the 3G as the strip patches and wave channels. The Russian division of the operators is the frequency, so choose the product carefully. Advance in Wikipedia inquire how MHz is on the internet at different operators. We believe that some figures can be taken from the technical characteristics of the modem. Of them and select the correct channel.

Recommended items to buy from well-known manufacturers, so as not to run into cheaters. With regard to giants such as Delta, plants have realized the need for 3G broadband antennas and release devices suitable for WiFi, and cellular - frequencies differ slightly, if not to take in the 5 GHz Attention. Permissible to buy an antenna for cellular phone - to the old versions will not work, and to have a special entrance - completely. If necessary, the connector is rearranged, and the good reception is guaranteed. Please note that these antennas are passive, do not be carried away by reducing the length of the cable.

A number of manufacturers are selling the device, similar to the screen, it is worth 3G-modem in its focus. This is called a screen assembly costs money. In fact, it is an ordinary sheet of metal, part of the boundary of the interference device and concentrates the signal. Already due to this can be done to improve communication speed, if you catch the beam. reception conditions are determined by the weather.

If you put an ordinary modem is in focus (or focal plane, offset from the center), you get a good idea. If the balcony is already antenna, play, remembering the simple law of physics: the angle of incidence equals the angle of reflection.

As multifeed allow satellites to catch a few at the expense of installing converters in a row, and the signal cell tower will catch at a single point on the focal plane of the same parabolic dish. We hope that showed how to buy an antenna for phone, modem, and other mobile devices. The key points are:

1. The value of the wave resistance.
2. The frequency of operation of the device.
3. Where to connect: not all manufacturers want to modernize the factory devices, hiding the antenna input. You will understand when you want to buy an antenna for modem megaphone.

It would be nice to create an active device, buy a power supply for the antenna, mount the amplifier. the signal level would be high. The most important thing is not to burn the modem, electronics do not like high voltage. Matching - a separate science, it only cover the review no chance.