Directional antenna

Directional antenna
Log-periodic dipole array

A directional antenna or beam antenna is an antenna which radiates greater power in one or more directions allowing for increased performance on transmit and receive and reduced interference from unwanted sources. Directional antennas like Yagi-Uda antennas provide increased performance over dipole antennas when a greater concentration of radiation in a certain direction is desired.

All practical antennas are at least somewhat directional, although usually only the direction in the plane parallel to the earth is considered, and practical antennas can easily be omnidirectional in one plane.

The most common types are the Yagi-Uda antenna, the log-periodic antenna, and the corner reflector, which are frequently combined and commercially sold as residential TV antennas. Cellular repeaters often make use of external directional antennas to give a far greater signal than can be obtained on a standard cell phone. Satellite Television receivers usually use parabolic antennas.

For long and medium wavelength frequencies, tower arrays are used in most cases as directional antennas.

See also



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  • directional antenna — Antenna An*ten na, n.; pl. {Antenn[ae]}. [L. antenna sail yard; NL., a feeler, horn of an insect.] 1. (Zo[ o]l.) A movable, articulated organ of sensation, attached to the heads of insects and Crustacea. There are two in the former, and usually… …   The Collaborative International Dictionary of English

  • directional antenna — An antenna or aerial that radiates and receives signals mainly from one direction. For terrestrial radio communications, directionality in an azimuth or a horizontal plane is important. Directional antennae are either monodirectional,… …   Aviation dictionary

  • directional antenna — kryptinė antena statusas T sritis fizika atitikmenys: angl. directional antenna; directional beam aerial; directive antenna vok. Richtantenne, f; Richtstrahlantenne, f; Richtungsantenne, f rus. направленная антенна, f pranc. antenne… …   Fizikos terminų žodynas

  • directional antenna — kryptinė antena statusas T sritis automatika atitikmenys: angl. directional antenna; directive antenna vok. Richtstrahlantenne, f; Richtungsantenne, f rus. направленная антенна, f pranc. antenne directionnelle, f …   Automatikos terminų žodynas

  • directional antenna — noun an antenna that transmits or receives signals only in a narrow angle • Hypernyms: ↑antenna, ↑aerial, ↑transmitting aerial • Hyponyms: ↑array, ↑dish, ↑dish aerial, ↑dish antenna, ↑ …   Useful english dictionary

  • non-directional antenna — įvairiakryptė antena statusas T sritis fizika atitikmenys: angl. non directional antenna; nondirective antenna; omnidirectional antenna vok. rundstrahlende Antenne, f; ungerichtete Antenne, f rus. ненаправленная антенна, f pranc. antenne… …   Fizikos terminų žodynas

  • end-on directional antenna — ašinio spinduliavimo antena statusas T sritis radioelektronika atitikmenys: angl. end fire antenna; end on directional antenna vok. Längsstrahler, m; Längsstrahlungsantenne, f rus. антенна осевого излучения, f; антенна продольного излучения, f… …   Radioelektronikos terminų žodynas

  • Antenna — An*ten na, n.; pl. {Antenn[ae]}. [L. antenna sail yard; NL., a feeler, horn of an insect.] 1. (Zo[ o]l.) A movable, articulated organ of sensation, attached to the heads of insects and Crustacea. There are two in the former, and usually four in… …   The Collaborative International Dictionary of English

  • antenna tower — Antenna An*ten na, n.; pl. {Antenn[ae]}. [L. antenna sail yard; NL., a feeler, horn of an insect.] 1. (Zo[ o]l.) A movable, articulated organ of sensation, attached to the heads of insects and Crustacea. There are two in the former, and usually… …   The Collaborative International Dictionary of English

  • directional — adj. 1. of or pertaining to direction (definition 2). [WordNet 1.5] 2. serving to indicate direction. [PJC] 3. (Radio) transmitting radio signals in a specific direction, or receiving signals only from a narrow angle of directions, thus serving… …   The Collaborative International Dictionary of English

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