The AN/APG-77 is a solid-state, active electronically scanned array radar developed by Northrop Grumman for the US Air Force F-22 aircraft. The AN/APG-77 consists of 1500 transmit\receive modules, each about the size of a gum stick, and can perform a near-instantaneous beam steering in the order of tens of nanoseconds. This advanced radar is fitted out with separate transmitter and receiver for each of the antenna's radiating elements to provide the agility, low radar cross section and wide bandwidth requested for the F/A-22. The APG-77 has a 120° field of view in azimuth and elevation and a power peak of 12kw.
Northrop Grumman have manufactured mor than 100 APG-77 AESA radars, and much of the technology developed for the APG-77 is being used in the APG-81 radar for the F-35 Lightning II. The APG-77 is more reliable, easy to repair, and maintainable than currently fielded aircraft radars through the use of solid state technology and elimination of mechanical moving parts.
The APG-77v1 was installed on F-22 Raptors from Lot 5 and on. This provided full air-to-ground functionality, such as high-resolution synthetic aperture radar mapping, ground moving target indication and track (GMTI/GMTT), automatic cueing and recognition, and combat identification.