Plain English Meaning

A radar that aims itself electronically instead of by spinning a dish, so it can look at many aircraft very quickly and refresh their positions much faster than older radars.

Full Definition

Radar antennas that steer their beam by electronically shifting the phase of signals across a fixed array of small radiating elements, rather than by physically rotating or tilting a dish. Because there are no moving parts to swing the beam, the radar can point in a new direction almost instantly and can update each aircraft's position many times per second.

Context Anchor

Seen in PRM radar discussions for monitoring aircraft on closely spaced parallel approaches.

Derivation

From 'electronic' (using electrical signals rather than mechanical motion) and 'scan' (to sweep across an area looking for something). The antenna 'scans' its beam across the sky electronically — by signals across many small elements — instead of physically sweeping a dish around.