Phased array transmission systems provide superior control of direction and mitigate unwanted electronic noise. They consist of microwave generators, wave guides, and amplifiers. Although all of the components in a phased array use the same frequency and amplitude they are out-of-phase with each other so that they can create constructive interference in the desired direction. Because of this, they do not need to physically change the angle of each element of the array, instead, changing the phase of the emitted microwaves facilitates a change in the overall angle of the beam.

Phased array focusing at an angle.	Phased array focusing at a 90 degree angle.
Images courtesy of Visualize Science

Examples of phased arrays consist of military devices such as surveillance, communication devices, and complicated radar devices.

In November, 2007, the University of California at San Diego announced that its electrical engineers had developed the world's most complex radio frequency integrated circuit. One of the most prominent military devices entirely using phased arrays is the Aegis combat system. This device is capable of tracking moving targets such as enemy missiles thus enabling our Navy to intercept the missile before impact. The Aegis missile tracking system is created by combining the SPY-1 radar, the Lockheed Martin-developed MK 41 Vertical Launching System, and the SM-3 missile.4



Another military example of a phased array is Israel's Arrow. This is an anti-ballistic missile system that uses a phased array tracking system called the Green Pine Radar. This radar can aquire many targets at once with many sets of phased array modules on one very large array.