What Is An Antenna?

Date First Published: 16th June 2022

Topic: Computer Networking

Subtopic: Network Hardware

Article Type: Computer Terms & Definitions

Difficulty Level: 5/10

Learn more about what an antenna is in this article.

Also known as an aerial, an antenna is a part of wireless infrastructure that is capable of sending and receiving microwave, radio, and satellite signals. It works by converting electricity into electromagnetic waves, such as micro or radio waves. Antennas are used in wireless LAN, mobile telephony, RFID tags, wireless routers, car stereos, Bluetooth-enabled devices, two-way radios, and satellite communication. They can send and receive waves from all directions.

Dish Antennas

Dish antennas are the most widely used antennas in computer and wireless communications for satellite communications. They are only practical at microwave frequencies above 3GHz and they consist of a dish-shaped reflector that is used for transmitting and receiving radio and TV signals from orbiting satellites.

The dish antenna collects RF from a distant source and focuses it on the active element. The active element radiates RF that is made parallel by the reflector to deliver in a specific direction.

History

Antennas were first built in 1888 by Heinrich Hertz, a German physicist in his experiments to prove the existence of waves that were predicted by the electromagnetic theory of James Clerk Maxwell. Heinrich Hertz placed dipole antennas at the centre of parabolic reflectors for both transmitting and receiving. In 1895, Guglielmo Marconi began to develop antennas that were practical for long distances and wireless telegraphy. As a result, he received a Nobel Prize.