Wikipedia
Antenna array is a systematic arrangement of radio antennas working together.
Kinds of antenna array include:
- Antenna array (electromagnetic), a geometrical arrangement of antenna elements with a deliberate relationship between their currents, forming a single antenna usually to achieve a desired radiation pattern
- Array factor, used to define an antenna array
- Phased array, An antenna array where the phase shifts (and amplitudes) applied to the elements are modified electronically, typically in order to steer the antenna system's directional pattern, without the use of moving parts
- Smart antenna, a phased array in which a signal processor computes phase shifts to optimize reception and/or transmission to a receiver on the fly, such as is performed by cellular telephone towers
- Interferometric array of radio telescopes or optical telescopes, used to achieve high resolution through interferometric correlation
- Watson-Watt / Adcock antenna array, using the Watson-Watt technique whereby two Adcock antenna pairs are used to perform an amplitude comparison on the incoming signal
An antenna array is a set of individual antennas used for transmitting and/or receiving radio waves, connected together in such a way that their individual currents are in a specified amplitude and phase relationship. The interactions of the different phases enhance the signal in one desired direction at the expense of other directions. This allows the array to act as a single antenna, generally with improved directional characteristics (thus higher antenna gain) than would be obtained from the individual elements.
The resulting array in fact is often referred to and treated as "an antenna," particularly when the elements are in rigid arrangement with respect to each other, and when the ratio of currents (and their phase relationships) are fixed. On the other hand, a steerable array may be fixed physically but has electronic control over the relationship between those currents, allowing for adjustment of the antenna's directionality without requiring physical motion.
The concept is widely used and has various names; one relatively common synonym is directional array. When used with a reflector to further improve the directionality, the result is a reflective array antenna. If each of the individual antennas within the array can be separately controlled, the result is a phased array.
Purposes include the production of a null to avoid co-channel interference with another transmitter.
Usage examples of "antenna array".
The highest item on Chicago's periscope was a miniature antenna array which fed signals to a broadband receiver.
The antenna array for gathering scientific data on the atmosphere festooned the domed roofs like the leafless branches of trees in winter.
Higher up was a complicated Yagi antenna array for two meters, vertically polarized and capable of being oriented for work in conjunction with moonbounce or OSCAR satellites.
With the new antenna array we can pick up bursts from up to six hundred light years out.
He's sittin' there at the base of the antenna array when his suit tells him there's this big ole rock floatin' up towards him.
The first was an open space view of the antenna array, now fixed in position or hunting so imperceptibly that the human eye could not tell the difference.
One huge antenna array, called an Elephant Cage for its circular configuration, both detected and localized signals, while other towering whip antennas handled other tasks.