With no moving parts and the ability to electronically steer beams in milliseconds, Active Electronically Scanned Array (AESA) radars offer performance, stealth and resilience for US military aircraft.

For decades, US military aircraft have used radar to perform a variety of critical functions, including detecting and tracking enemy aircraft.

Traditional radar systems have long relied on large rotating antennas to send out pulses of radio waves, which bounce off objects and return to the source.

These older systems rely on mechanical steering and can only point in one direction at a time, are slower to respond to fast-moving targets and are easier for enemy systems to detect and jam.

Older Passive Electronically Scanned Array (PESA) radars also use a single central transmitter to produce a radar signal, which is then distributed across the antenna elements.

In contrast, AESA radars use a computer-controlled antenna array that is made up of numerous tiny antenna elements with individual solid-state transmit/receive modules (TRMs).

TRMs can each transmit and receive signals independently.

This modular architecture enables multiple simultaneous beams that can be electronically steered to point in different directions without moving the antenna, enabling multiple functions at once, all without mechanical repositioning.

A tactical advantage

The result is a radar system that is not only faster but far more versatile and reliable.

The distributed design allows AESA radars to compensate for intermittently malfunctioning modules and eliminates the single‑point failure weakness common in mechanically scanned radars.

US fighter jets such as the F-22 Raptor, the F-15E Strike Eagle, the F-35 Lightning II, the F/A-18 E/F Super Hornet and the F-16 Fighting Falcon are equipped with AESA systems.

AESA radars are particularly critical for stealth aircraft.

Compared to older systems, AESA radars can send out multiple beams of radio waves at multiple frequencies simultaneously, spreading their signal emissions across a wider range of frequencies.

This makes them more difficult to detect over background noise, and allows aircraft to radiate powerful radar signals while still remaining stealthy.

AESA radars also are more resistant to jamming.

In conventional jamming, adversaries pick off the radar's operating frequency and interfere with it. But rapid frequency shifts render that ineffective as jammers have difficulty keeping up.

AESA-equipped stealth aircraft like the F‑35 and F‑22 can also act as force multipliers.

Their ability to gather intelligence, detect adversaries at stand-off ranges, coordinate with other assets and resist electromagnetic interference gives the US Air Force a broad operational edge.