Active antenna

An active antenna is an antenna that contains active electronic components, as opposed to typical passive components. A passive antenna typically resembles a dipole antenna.

An active design allows the construction of antennas of limited size and / or wide frequency range, and are primarily used in situations where a simpler and more receptive large antenna is either impractical (inside a portable radio) or impossible (suburban residential area that disallows use of large outdoor low-frequency antennas).