An antenna, otherwise known as an arial, is a device created to send or receive signals through air waves. The word antenna comes from the Latin, meaning, "sail yard." There are many types of antennae and many ways to categorize them. Man-made antennas are made for the basic purpose communication: to send and receive signals, signs and other forms of communication. They are mostly metal and have many different designs, sizes, and shapes.

The major categorical division between those devices that transmit signals called "transmitting antennas" and those that receive signals called "receiving antennas." It is possible to have antennas that function as both, that is, for transmitting and receiving signals. However, transmitting units can handle a great deal more energy than receiving antennas.

Antenna types can be used to differentiate between those used for radio, television, radar systems and much more. Since antennae can be built for transmission on different frequencies, another way to categorize them is by their frequency. For a radio antenna, it is important to know whether they are built for frequency modulation (FM) which broadcasts at 88-108 MHZ (megahertz) or amplitude modulation (AM) which broadcasts at 535-1605 KHZ (kilohertz). For television antennae, you can distinguish between UHF (ultra high frequency) and VHF (very high frequency) antennas or perhaps even those which pick up both.

Stores selling these devices categorize antenna types as short, medium, or long to suit customers needs. For example, if customers want to buy a television antenna, their decision will depend on how close they are to the transmitting towers that they wish to pick up the signal from. If the range is well matched to the distance, it will prevent the antenna from picking up unwanted signals. The location is another way of looking at buying these signal transmitters. They can be made for indoor installation, outdoor installation, and attic installation as well. The installation is easy for indoor antennas but usually they do not have the elevation to provide the best signal, unfortunately, for customers who are far from transmission towers. Earlier, outdoor antennas were primarily made for rooftops but now more and more of these are designed to be mounted on the side of a house, or on a deck, etc. The attic is a useful installation location for those who don't want their antenna visible inside or outside.

Portable antennas will always come in handy as they can be carried and used anywhere. There is no shortage of these available in the market for television, radio, and radar systems.

Antennas play a vital role in a variety of fields, and there are definitely types suit everyone's need and budget. Browse online to find more information or for the best deals available.