What you need to know about antennas in cellphones

Antenna - the most important part of your phone, and sometimes - even an element of design. In this article we describe the types of antennas, as well as how to talk on a cell phone, and why it is important to know where the phone antenna is located.

The antenna in the phone is important for two reasons: it affects the quality of reception and transmission of signals, and determines the exposure of high frequency, when you use your phone to your ear. Radiation of mobile phones - a serious issue for those who think about their health. Antenna phone emits a strong signal in the frequency range of the standard cellular. In fairness, we note that there is still not entirely clear what effect the high-frequency radiation of mobile phone per person. While the work on assessing the "harm" phones being a long time (more than 15 years), until, fortunately, the presence of the harmful effects of mobile phones on human health has not been proved.

Despite this, in some countries already have serious restrictions on the use of mobile phones by children.

Now - about the types of antennas. Currently, the phones were the most common following types of antennas:

- Internal (Patch antenna, PIFA antenna), hidden in the casing and invisible;
- Whip antenna or a shortened dipole (Stub antenna), sticking out of the shell as a stump;
- Extendable antenna (Retractable antenna), made of thin telescopic tubes and hidden in the body;
- Combinations of these antennas.

Inner - one of the most common and perhaps the most user-friendly dish, completely hidden inside the phone.She never breaks because of careless handling, and has good technical characteristics. The lack of such an antenna only that, buying a mobile phone, you just do not know where it is located in the body of the phone.On why this should know - a little later.

Recently has another kind of internal antenna - such antennas slightly protruding from the shell, but for the most part are located inside the phone. The need for such antennas has arisen with the trend towards the creation of thin phones - should be the same as a build a good antenna in a flat phone. However, it should be noted that a good small, flat and cheap antenna for mobile phone has not yet been developed.

The truncated dipole or the probe. This antenna has a very good performance, perfectly visible, but is inconvenient for the user. As the prevalence - the first place among manufacturers of low-cost mobile phones, as it is the cheapest type of antenna. Such antennas are often and easily broken by inaccurate subscribers.

The pull-out antenna or a telescope. In Europe and Russia, this antenna is now found mainly in older GSM-phones. In CDMA-phones, by contrast, the telescope is used quite often. In Asian countries (Japan, for example) and America (for example, in the U.S.) such antennas are still popular. The reason - the excellent performance and ease of execution - all this is important for the producer.

Such antennas frequently break and require delicate handling. It must be remembered that the phone with a telescope must be (not all manufacturers, however, follow this rule) work just fine, even if you do not put forward an antenna from the case until the end. Many do not realize this and fully nominate antenna at each call. In fact, putting forward a telescope, you are only slightly improves the technical parameters of the antenna and increase the level of the signal.

This is usually only helps when working in the area of poor coverage or weak signal strength, but in general has no effect.

There are other types of antennas, and even combinations of those already mentioned. Note that in the mobile phone may be not one but two major emitting antenna. Two antennas, for example, put in phone 3G (combined UMTS / GSM or CDMA / GSM). Bad in that there is nothing, just have to know where these antennas are located.

In the mobile phone in addition to the main radiating antenna may be more antenna and Bluetooth (BT) or antenna GPS (Global Positioning System).

Tue-antenna operates at frequencies of about 2.4 GHz and the level of radiation hundreds of times weaker than the radiation of the main antenna.

Now why you need to know where is situated the main antenna (or antenna) on your phone.

First, knowing where to place the antenna, you will not be a chance to catch it or touch her in conversation. It would be nice if every manufacturer's manual specifies the location of the antenna in the phone. Also, it would be nice to indicate in the manual that relate to the antenna during a call is not recommended. No, it's not dangerous, just holding on for the antenna on the telephone, you worsen his work. Without going into technical details, we can say that the antenna with his hand pressed to her could significantly worse than working at the reception and transmission. This leads to the fact that the radius of the cell, ie area where your phone works reliably, is significantly reduced. In each case, everything will depend on the type of antenna, from its location in the body and how it hinders the work of the owner of the phone.

Moreover, if the conversation you are hindering the work of the antenna, the power consumption of the battery of your phone can grow 2-fold or more.

This happens because of the changing balance of power channel - the phone increases the power of radiation at the direction of the network controller.

Here are the final estimates for conventional GSM-phone. If you change the antenna characteristics due to the fact that it is wrong, hold the phone, then

- The radius for your cell phone is reduced to 20%, and the cover - up to 30%, which can lead to complete loss of connection, for example, you dial the number - everything is in order, start to talk, touch the antenna - a connection is interrupted;
- Resource of your battery when talking faster by 20-60%, ie battery time is reduced more than 2 times.

All this is particularly noticeable in the countryside, where signals are weak, that is a great distance from the station cellular operator.

Moreover, when you simply pressed the phone to your ear during conversation and while holding it correctly, your phone's signal levels at the reception and transmission may deteriorate. Sometimes, in times when the antenna is bad. All this depends on the type of antenna, from its location in the body of the phone and from its proximity to the head, on the phone model. In varying degrees, all mobiles is exposed to and do not think that by buying an expensive phone, you get rid of all the problems. Check the same degradation parameters is possible only in specially equipped laboratories.

A reasonable question, but how to call correctly, without compromising the quality of work? How to keep the phone if you do not have ears?

The answer is simple. Correctly call should not pressing the phone to the head / ear, and not holding onto it with his hands. The best way to use Bluetooth or headphones, and the phone kept separately (eg in a bag), away from the metal surfaces.

Where can be located built-in antennas? Antenna invisible "are, basically, at the top of the phone, and often very close to straight to the dynamics that you apply to your ear. Less often, the antenna is located at the bottom of the phone. In some "clamshells" antenna hidden in the middle - at the top of the keyboard compartment. Most antennas are located in the thickened body.

Know where the antenna is useful for another reason - in this case you less irradiation of a high-power (which is strongly not recommended to do, whether installed from this injury or not), or reduce the intensity of such exposure. Reducing the intensity is achieved simply through the correct positioning of the phone on his head - the distance between the radiating antenna and the head / ear should be as much as possible. It must be remembered that increasing the distance of a few centimeters, you lessen the intensity of the high-frequency radiation in the head several times.

In order to have spoken about the dangers of radiation cell phones, remember the main thing - the microwave radiation is good for your body, surely will not bring.

It is worth adding that the working frequency of the phone close to the microwave oven. This means that the physical mechanism of the effect on bio-objects in both cases is identical - is the internal heating of the tissue, and increases its temperature. Of course, power the phone hundreds of times less than the power the stove, but you use a source of radiation directly to the head. Draw your own conclusions.