This article may be too technical for most readers to understand. Please help improve it to make it understandable to non-experts, without removing the technical details.(March 2024) (Learn how and when to remove this message)
Animation showing how a phased array works. It consists of an array of antenna elements (A) powered by a transmitter (TX). The feed current for each element passes through a phase shifter (φ) controlled by a computer (C). The moving red lines show the wavefronts of the radio waves emitted by each element. The individual wavefronts are spherical, but they combine (superpose) in front of the antenna to create a plane wave. The phase shifters delay the radio waves progressively going up the line so each antenna emits its wavefront later than the one below it. This causes the resulting plane wave to be directed at an angle θ to the antenna's axis. By changing the phase shifts, the computer can instantly change the angle θ of the beam. Most phased arrays have two-dimensional arrays of antennas instead of the linear array shown here, and the beam can be steered in two dimensions. The velocity of the radio waves shown have been slowed down.Animation showing the radiation pattern of a phased array of 15 antenna elements spaced a quarter wavelength apart as the phase difference between adjacent antennas is swept between −120 and 120 degrees. The dark area is the beam or main lobe, while the light lines fanning out around it are sidelobes.
In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas.[1][2][3][4][5][6][7][8][9][10][excessive citations]
The general theory of an electromagnetic phased array also finds applications in ultrasonic and medical imaging application (phased array ultrasonics) and in optics optical phased array.
In a simple array antenna, the radio frequency current from the transmitter is fed to multiple individual antenna elements with the proper phase relationship so that the radio waves from the separate elements combine (superpose) to form beams, to increase power radiated in desired directions and suppress radiation in undesired directions. In a phased array, the power from the transmitter is fed to the radiating elements through devices called phase shifters, controlled by a computer system, which can alter the phase or signal delay electronically, thus steering the beam of radio waves to a different direction. Since the size of an antenna array must extend many wavelengths to achieve the high gain needed for narrow beamwidth, phased arrays are mainly practical at the high frequency end of the radio spectrum, in the UHF and microwave bands, in which the operating wavelengths are conveniently small.
Phased arrays were originally conceived for use in military radar systems, to steer a beam of radio waves quickly across the sky to detect planes and missiles. These systems are now widely used and have spread to civilian applications such as 5G MIMO for cell phones. The phased array principle is also used in acoustics, and phased arrays of acoustic transducers are used in medical ultrasound imaging scanners (phased array ultrasonics), oil and gas prospecting (reflection seismology), and military sonar systems.
The term "phased array" is also used to a lesser extent for unsteered array antennas in which the phase of the feed power and thus the radiation pattern of the antenna array is fixed.[8][11] For example, AM broadcast radio antennas consisting of multiple mast radiators fed so as to create a specific radiation pattern are also called "phased arrays".
^Brown, Arik D. (2021). Active Electronically Scanned Arrays: Fundamentals and Applications. Wiley-IEEE Press. ISBN 978-1-119-74905-9.
^Brown, Arik D. (2012). Brown, Arik D. (ed.). Electronically Scanned Arrays: MATLAB Modeling and Simulation, 1st Ed. CRC Press. doi:10.1201/b12044. ISBN 9781315217130.
^Milligan, Thomas A. (2005). Modern Antenna Design, 2nd Ed. John Wiley & Sons. ISBN 0471720607.
^Balanis, Constantine A. (2015). Antenna Theory: Analysis and Design, 4th Ed. John Wiley & Sons. pp. 302–303. ISBN 978-1119178989.
^Stutzman, Warren L.; Thiele, Gary A. (2012). Antenna Theory and Design. John Wiley & Sons. p. 315. ISBN 978-0470576649.
^Lida, Takashi (2000). Satellite Communications: System and Its Design Technology. IOS Press. ISBN 4274903796.
^Laplante, Phillip A. (1999). Comprehensive Dictionary of Electrical Engineering. Springer Science and Business Media. ISBN 3540648356.
^ abVisser, Hubregt J. (2006). Array and Phased Array Antenna Basics. John Wiley & Sons. pp. xi. ISBN 0470871180.
^Golio, Mike; Golio, Janet (2007). RF and Microwave Passive and Active Technologies. CRC Press. p. 10.1. ISBN 978-1420006728.
^Mazda, Xerxes; Mazda, F. F. (1999). The Focal Illustrated Dictionary of Telecommunications. Taylor & Francis. p. 476. ISBN 0240515447.
^ This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22. (in support of MIL-STD-188). Definition of Phased Array Archived 2004-10-21 at the Wayback Machine. Accessed 27 April 2006.
In antenna theory, a phasedarray usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio...
Phasedarray ultrasonics (PA) is an advanced method of ultrasonic testing that has applications in medical imaging and industrial nondestructive testing...
active electronically scanned array (AESA) is a type of phasedarray antenna, which is a computer-controlled antenna array in which the beam of radio waves...
PhasedArray Radar Qadir (Persian: رادار آرایه فازی قدیر) is an Iranian radar with a range of 1100 km and capable of tracking targets to a height of 300 km...
wave tube) and/or receiver. The largest use of phasedarrays is in radars[citation needed]. Most phasedarray radars in the world are PESA[citation needed]...
The Solid State PhasedArray Radar System (SSPARS, colloquially "BMEWS radar network'" as late as 2004) is a United States Space Force radar, computer...
PAVE PAWS (PAVE PhasedArray Warning System) is a complex Cold War early warning radar and computer system developed in 1980 to "detect and characterize...
the beam. Some antenna arrays (such as military phasedarray radars) are composed of thousands of individual antennas. Arrays can be used to achieve higher...
Active PhasedArray Radar (APAR) is a shipborne active electronically scanned array multifunction 3D radar (MFR) developed and manufactured by Thales Nederland...
Multifunction PhasedArray Radar (MPAR) was an experimental Doppler radar system that utilized phasedarray technology. MPAR could scan at angles as high...
separate sub-arrays of different types of antenna elements that will make up the SKA-low, SKA-mid and survey arrays: SKA-low array: a phasedarray of simple...
parabolic antenna. Another method of steering is used in a phasedarray radar. Phasedarray antennas are composed of evenly spaced similar antenna elements...
and spacecraft tracking. The northernmost station of the Solid State PhasedArray Radar System, the military installation was built as the 1st site of...
phaser can be set to "stun" or "kill". Phasers are common and versatile phasedarray pulsed energy projectile weapons, first seen in the original Star Trek...
phase shift module is a microwave network module which provides a controllable phase shift of the RF signal. Phase shifters are used in phasedarrays...
Clear's AN/FPS-123 Upgraded Early Warning Radar is part of the Solid State PhasedArray Radar System (SSPARS) which also includes those at Beale AFB, Cape Cod...
approximately 4,000 m2 (43,000 sq ft). Each antenna is equipped with a phased-array feed (PAF), significantly increasing the field of view. This design provides...
primary radars of RAF Fylingdales are active electronically scanned array (AESA) phasedarray radars, mounted on each face of a truncated tetrahedron, typically...
Linear diode array used in image scanners Microphone array Parametric array of transducers Phased-array optics Photovoltaic array Staring array, an imaging...
Technologies was selected to develop the CEAFAR Active PhasedArray Radar and CEAMOUNT Active PhasedArray Illuminator, as part of the Anti-Ship Missile Defense...
A virtually imaged phasedarray (VIPA) is an angular dispersive device that, like a prism or a diffraction grating, splits light into its spectral components...
Global Information
This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22. (in support of MIL-STD-188). Definition of Phased Array Archived 2004-10-21 at the Wayback Machine. Accessed 27 April 2006.
