India’s active electronically scanned array is controlled by computer and this array antenna is responsible to steer the beam of radio waves in order to point in different directions without moving the antenna. This is done electronically. In this technology, under the control of a computer, each antenna element is linked to a small solid-state transmit/receive module that performs the functions of a transmitter and/or receiver to the antenna. It gets compared with a passive electronically scanned array, PESA. All the antenna elements are linked to a single transmitter and/or receiver to PESA. These are connected through phase shifters under the control of the computers. In the battlefield, AESA are mainly used in radar, and these are known as active phased array radar.
We can say that the active electronically scanned arrays are a more superior and sophisticated, second-generation of the original PESA phased array technology. PESAs can radiate one beam of radio waves at a single frequency at a time, but the AESA can emit multiple beams of radio waves at multiple frequencies at the same time. The active electronically scanned array radars can spread their signal emissions across an extensive range of frequencies that makes them trickier to notice over background noise, by allowing ships and aircraft to radiate powerful radar signals and still remaining quiet. However, most of the radar systems used in modern combat aircraft are AESA systems.