Antennas are an essential part of modern communication systems, and they are used in cars, cell phones, and home stereos. But how do they work? In this post, we’ll explore the basics of how a car antenna works.
An antenna is essentially a piece of wire that radiates electromagnetic energy. To make an antenna work, we need to change the way the current flows through the wire. If we have two pieces of wire side-by-side, the electromagnetic energy that is generated from current flow cancels each other out. However, if we separate the two wires, we now have an energy field that radiates out into space.
A simple dipole antenna, like the one you might find on your FM stereo at home, is just a wire split in two that generates RF energy that leaves like this and can be received as well. Most antennas act very similar to a dipole antenna.
To transmit power out to the air, we need to use coaxial cable. Coaxial cable has a shield on the outside, an insulator, and a center conductor. The center conductor runs the power to the antenna, while the shield on the outside is grounded. This allows the current to flow in two directions on the inside, generating an energy field that radiates out into space.
But how does an antenna receive energy? A cell tower, for example, is radiating energy just like our antenna. This energy can be captured by the same antenna and transferred down to our feed point. From there, it can be run into an amplifier or plugged straight into a stereo system.
In conclusion, antennas are an essential component of modern communication systems, and they work by generating an energy field that radiates out into space. While most antennas act very similarly to a dipole antenna, understanding the way the current flows through coaxial cable is crucial to making an antenna work.