AESA
Active Electronically Scanned Array
Active Electronically Scanned Array is a type of radar that uses thousands of individual transmit/receive modules to steer its beam electronically, enabling simultaneous tracking and jamming across multiple frequencies.
An Active Electronically Scanned Array (AESA) radar represents the current state of the art in airborne and shipborne radar technology. Unlike older mechanically scanned radars that physically rotate an antenna to sweep a beam across the sky, an AESA uses hundreds or thousands of small transmit/receive (T/R) modules, each capable of generating and receiving its own radar signal. The beam is steered electronically by adjusting the phase and timing of signals across the array.
This architecture gives AESA radars enormous advantages. They can track hundreds of targets simultaneously, switch between air-to-air and air-to-ground modes almost instantly, operate at multiple frequencies to defeat jamming, and even function as electronic warfare systems themselves. The AN/APG-81 on the F-35 and the AN/APG-82 on the F-15EX are among the most capable AESA radars in service.
AESA technology has become a defining feature of modern combat aircraft. Fourth-generation fighters are being retrofitted with AESA radars to extend their relevance, and the technology is increasingly appearing on naval vessels, ground-based air defense systems, and even unmanned aircraft.
Related Terms
PESA(Passive Electronically Scanned Array)
Passive Electronically Scanned Array is a radar that uses a single transmitter and steers its beam electronically through phase shifters, offering faster scanning than mechanical radars but less flexibility than AESA.
RCS(Radar Cross Section)
Radar Cross Section is a measure of how detectable an object is by radar, expressed in square meters. A smaller RCS means the object is harder to detect.
EW(Electronic Warfare)
Electronic Warfare encompasses all military actions that use electromagnetic energy to control the electromagnetic spectrum, including jamming, deception, and electronic intelligence gathering.
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An AESA radar fires thousands of independent beams simultaneously. Each beam can track a different target, operate on a different frequency, and switch modes in microseconds. Here's how modern military radar actually works, from the physics of T/R modules to the systems that make the F-35, F-22, and Navy destroyers see everything.
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