Passive electronically scanned array: Difference between revisions

Revision as of 22:49, 7 December 2016

Revision as of 00:08, 8 December 2016

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[[File:DN-ST-92-02246.JPEG|thumb|The [[Mikoyan MiG-31]] combat aircraft with nose fairing removed, showing its [[Zaslon]] Passivepassive electronically scanned array onradar [[Mikoyanantenna. MiG-31]]]]

[[File:Phased array animation 10 frames 371x400px 100ms.gif|thumb|upright=1.2|Animation showing how a passive electronically scanned array works. It consists of an array of antenna elements ''(A)'' powered by a single [[transmitter]] ''(TX)''. The feed current for each antenna 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 ([[superposition|superpose]]) in front of the antenna to create a [[plane wave]], a beam of radio waves travelling in a specific direction. 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 to the antenna. The velocity of the radio waves is shown slowed down enormously.]]