What is active phased array?

Active phased array is a type of antenna that uses electronic steering to direct radio waves in specific directions. It consists of multiple individual antennas known as "elements" that can be controlled individually to transmit or receive signals in a specific direction. These elements are connected to a central control unit called the "phased array controller" that controls their phase and amplitude. By changing the direction and intensity of each element, the antenna can generate a beam of radio waves that can be precisely aimed and focused.

Active phased array antennas have several advantages over traditional antennas. They can be used for both transmitting and receiving signals, they can switch between multiple beams of radio waves quickly, and they can track moving objects. They are commonly used in radar systems, communication systems, and satellite systems.

Some examples of active phased array antennas include the AN/APG-77 radar used in the F-22 Raptor fighter jet, the SPY-1 radar used in the Aegis Combat System on Navy ships, and the phased array antenna on the Hubble Space Telescope.