Browse Definitions:
Definition

omnidirectional antenna

An omnidirectional antenna is a wireless transmitting or receiving antenna that radiates or intercepts radio-frequency (RF) electromagnetic fields equally well in all horizontal directions in a flat, two-dimensional (2D) geometric plane. Omnidirectional antennas are used in most consumer RF wireless devices, including cellular telephone sets and wireless routers.

In theory, a vertically oriented, straight conductor such as a dipole antenna measuring no more than 1/2 wavelength from end-to-end always exhibits omnidirectional properties in a horizontal (azimuth) plane. Multiple collinear (in-line) vertical dipoles also exhibit omnidirectional behavior in the azimuth plane; they can offer improved performance over a single dipole in some applications. If the conductor axis is not oriented vertically, then the antenna radiates and receives equally well in all directions in the plane through which the conductor passes at a right angle. However, this ideal state of affairs exists only in the absence of obstructions or other nearby conducting objects. In practice, surrounding objects (such as the user of a cell phone set or a computer next to a wireless router) distort the radiation and reception pattern.

In the usual context, a so-called omnidirectional antenna does not perform equally well in all possible directions in three-dimensional (3D) space. Such a device, which can exist only in theory but can be approached in practice, is called an isotropic antenna or isotropic radiator.

Antennas that offer enhanced performance in some directions, at the expense of other directions, are called directional antennas or directional radiators. The most common example is the dish antenna used with satellite internet, satellite television, and space-communications installations. Other examples include the Yagi antenna, quad antenna, billboard antenna, and helical antenna.

 

This was last updated in December 2016

Continue Reading About omnidirectional antenna

Join the conversation

1 comment

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

In theory an omnidirectional antenna is capable of picking up or transmitting signals from/to any direction, but this cannot be achieved entirely in practice, because the limitation placed by objects that surround the antenna which alter or distort its propagation field. This field is further distorted if the antenna is horizontally polarized. All practical omni antennas have these limitations. http://www.omnitenna.com
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

SearchSecurity

  • password

    A password is an unspaced sequence of characters used to determine that a computer user requesting access to a computer system is...

  • adware

    Adware is any software application in which advertising banners are displayed while a program is running.

  • botnet

    A botnet is a collection of internet-connected devices, which may include PCs, servers, mobile devices and internet of things ...

SearchHealthIT

SearchDisasterRecovery

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

  • mass notification system (MNS)

    A mass notification system is a platform that sends one-way messages to inform employees and the public of an emergency.

  • disaster recovery as a service (DRaaS)

    One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

SearchStorage

  • data migration

    Data migration is the process of transferring data between data storage systems, data formats or computer systems.

  • compact disc (CD)

    A compact disc is a portable storage medium that can be used for recording, storing and playing back audio, video and other data ...

  • secondary storage

    Secondary storage is used to protect inactive data written from a primary storage array to a nonvolatile tier of disk, flash or ...

SearchSolidStateStorage

  • SSD RAID (solid-state drive RAID)

    SSD RAID (solid-state drive RAID) is a methodology commonly used to protect data by distributing redundant data blocks across ...

  • Tier 0

    Tier 0 (tier zero) is a level of data storage that is faster, and perhaps more expensive, than any other level in the storage ...

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close