Antennas

Antenna are actually transducers that are primarily designed to transmit or receive electromagnetic waves as signals. Antennas convert electromagnetic waves into electrical currents and convert electrical currents into electromagnetic waves. Antennas are used in systems such as radio and television broadcasting, point-to-point radio communication, wireless LAN, radar, and space exploration. Antennas usually work in air or outer space, but can also be operated under water or even through soil and rock at certain frequencies for short distances. There are two principal types of antennas, which, are either: Omni-directional (radiates equally in all directions), such as a vertical rod or Directional (radiates more in one direction than in the other). All antennas radiate some energy in all directions in free space but careful construction results in substantial transmission of energy in a preferred direction and negligible energy radiated in other directions.