It’s probably not something lots of people are interested in unless they’re some sort of an electrical engineer or just bored, however understanding how a dipole antenna works can be useful when the one on your TELEVISION or radio goes south on you and the factor is beyond your comprehension.
Trying to discuss how a dipole antenna works in simple English is not a simple job as there are a lot of technical requirements that need to be described. But a general understanding is possible without entering into tech speak that would make Einstein cringe.
In order for an antenna to work it needs to radiate. Your antenna, whether TV or radio has exactly what is called complimentary electrons going through it. It is these complimentary electrons that vibrate. The question becomes, how do these complimentary electrons vibrate and exactly what triggers them to vibrate?
Well, in real life it takes an electrical field to move an electron. If you take a separated straight dipole, the power comes from the integrated fields of all the charged particles, both favorable and unfavorable, in the antenna. We’ll call this field the antenna’s coulomb field.
In addition to this field, the antenna shows a magnetic field that is the amount of the electromagnetic fields of all the complimentary moving electrons. The dipole antenna likewise has a dynamic electrical field that is the vector sum of the vibrant electric fields of all the totally free electrons. What we can do is separate the electrical field of the antenna at any point in area into two elements. Among the parts will remain in stage with the overall electromagnetic field and the other will be 90 degrees out of stage. The in-phase element is the radiation field of the antenna and the out of stage component is the induction field. At the antenna, both fields are parallel to the metal surface area.
Exactly what takes place is that the coulomb field and the induction field fall off much more rapidly than the radiation field as the range increases from the dipole antenna. When you reach distances greater than a couple of wavelengths from the antenna, you have exactly what is called the antenna’s far field. This field is pure radiation. As you get closer to the antenna you have what is called the antenna’s near field. This field is a mix of radiation, coulomb, and induction fields. Still with us? Great, we’re getting to the excellent part.
What eventually occurs with all these fields that makes it so that your TELEVISION or radio gets signals through your dipole antenna bought from antenna-connector.com is this. The complimentary electrons moving through your antenna are moving at their maximum speed. The right hand half of your antenna collects electrons. The left hand half of your antenna is where the electrons leave and leave an excess of charged ions. The coulomb field produces an imbalance and opposes the electrons’ rightward motion. The electrons then stop, coast for a bit and then head back towards the left. After they reach maximum speed they then stop and procedure is duplicated, now heading back to the right. The outcome is a vibration of complimentary electrons that warms the metal and in turn produces electromagnetic waves.