Wednesday, November 11, 2009

How Antennas Work

A simple English explanation of what happens inside your TV or radio antenna, that the signals and to which your device, they can receive.

It's probably nothing, what many people are interested if they can understand some sort of electrical engineering, or just boring, but how does an antenna be useful if the one on your TV or the radio goes south on you and The reason for this is about your understanding.

The attempt to explain how an antenna works in plain English is no easy task, as there are a variety of technical specifications that it can be explained. But would be a general understanding without speaking in technology that makes it possible to crawl Einstein.

In order for an antenna to work has to shine. Your antenna, whether on television or radio is, what flowing free electrons is. It is these free electrons, vibrating. The question is, how can swing these free electrons and what does it vibrate?

OK, in real life, it takes an electric field to move an electron. If you take an isolated straight dipole, the power comes from the combined fields of all charged particles, both positive and negative, in the antenna. We will call this area the antenna Coulomb field.

In addition to this area, the antenna has a magnetic field that the sum of the magnetic fields of all the free-moving electrons. The antenna is also a dynamic electric field, which is the vector sum of the dynamic electric fields of all the free electrons. What we can do is the electric field of the antenna at any point in space separated into two components. One of the components is in phase with the total magnetic field and the other 90 degrees out of phase. The in-phase element is the radiation field of the antenna and the out of phase element is the induction field. At the antenna, both parallel to the metal surface.

What happens is that the Coulomb field and the induction field fall off much faster than the radiation field with increasing distance from the antenna. When you reach a distance of more than a few wavelengths from the antenna, you have the so-called far-field antenna. The closer to the antenna you have what is called an antenna in the vicinity.

What happens ultimately with all of these areas that make it so that your TV or radio signals take over your antenna? The free electrons move through your antenna with the maximum speed. The right half of your antenna collects electrons. The left half of your antenna is where the electrons and let go a surplus of charged ions. The Coulomb field produces an imbalance, and stop right on the electrons' motion. The electrons then coast a little and then left his head. After they reach the maximum speed then stop and process repeats itself, is now heading back to right. The result is an oscillation of free electrons that the metal is heated and in turn, generates electromagnetic waves.


Back to TOP