AESA (active electronically scanned array) radar systems are used on a variety of different military platforms, including fighter aircraft, UAVs (unmanned aerial vehicles), drones, and naval vessels, and may also be used as a static ground-based defense capability.
They may be used to provide target detection and tracking capabilities, and can track large numbers of moving objects such as enemy aircraft and missiles at once. They may also be used as a fire-control radar, providing weapons systems with targeting information such as azimuth, elevation, and range.
Active Phased Array Radar
AESA radar uses a phased array antenna system made up of multiple antenna elements that each have their own separate transmit and receive module. Also known as active phased array radar, these radar systems are an upgrade to the older PESA (passive electronically scanned array) technologies which only provide one transmitter/receiver shared across all antenna elements. AESA radars can thus transmit multiple beams at multiple frequencies.
AESA vs PESA
AESA radars provide a number of advantages over PESA systems. The independent transmit/receive modules allow the system to carry out multiple functions simultaneously, with scans at different frequencies providing more detailed information. Using signals at multiple frequencies also allows the radar broadcasts to hide more effectively among background noise, making it harder to detect or intercept.
AESA radar systems are also harder to jam, as the multiple transmit/receive modules allow the system to change frequency with every pulse, and can even use random sequences, making it hard for the jammer to keep up.
As AESA antennas are made up of many elements, this means that there is no single point of failure, resulting in higher reliability and the ability to continue operation if one element does fail. AESA radar systems also have fewer moving parts than older mechanically scanning radars, which also means highly reliability and longevity.