Latest Trends in Active Electronically Scanned Antennas (AESAs)

AESA systems use active arrays, each with hundreds or even thousands of antennas. Each antenna has its own phase and gain control. The interference or superposition of individual wavefronts from the antenna elements is used to create a plane wave, effectively generating a beam of radio waves traveling in a specific direction. By shifting the phase of the antenna elements, AESA radar systems electronically steer the beams.

The antenna elements are typically spaced at half-wavelength to decrease exposure in the near field. AESA radars are also often required to spread their signals across a wide range of high frequencies. This frequency agility allows them to quickly search across a sector for targets. It also makes them more difficult to detect over background noise. This allows ships and aircraft to radiate powerful radar signals while remaining stealthy and more resistant to jamming.