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An antenna can be almost anything. Any conductor of electricity is a kind of antenna. Even a person shuffling their feet can be considered an antenna because they receive a signal from one place and transmit it to another.
However, the most typical antennas used to receive television and radio signals are usually made up of a dipole antenna. This antenna is basically a long tube of metal placed in a high place. Even rabbit ear television antennas are dipole antennas. Some of the larger television antennas have multiple dipoles so the maximum number of wavelengths can be captured.
The materials used to create an antenna are usually metal; aluminum is a common material. Inside the antenna is a coaxial cable, which is usually made up of copper or aluminum wire inside an insulated coating. The coaxial cable connects to the television or radio, and it is how the signal is translated into the images and sound. - The signals that antennas receive are different kinds of wavelengths. The radio and television waves that are picked up by antennas are usually high frequency electromagnetic signals, which are known as very high frequency (VHF) and ultra high frequency (UHF) signals. Most television signals have wavelengths varying anywhere from 54 mega hertz to 500 megahertz. Each television station or radio station broadcasts slightly different wavelengths. The antenna picks up the different signals and translates them into the different stations.
- Although the digital television signals are broadcast on a different frequency, all antennas can pick up the signal. The difference between analog and digital antennas is the cable attached to the antenna that translates the signals into viewable form. This is why owners of older antennas and televisions must use converter boxes to read the new signals. The digital signals are broadcast in shorter wavelengths, which make the distance that the waves travel shorter before they become distorted. Many people who were able to watch analog television through an antenna are no longer able to pick up the same stations through digital television signals due to the shorter wavelengths.
