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Designed for the F-22 Raptor fifth generation fighter, or, as some might say, the F-22 is designed around the Northrop Grumman AN/APG-77 active electronically scanned array multifunction radar, this is the electronic heart of the aircraft. [1] The radar, mounted in the F-22's nose, is closely coupled with an infrared scan-and-track (IRST) system; to achieve the same 120 degree coverage from either side of the nose, there are three infrared sensors, one in the nose and one in either wing. Coupling is easier in the F-22, as the radar computing is part of the main aircraft processors, rather than in a dedicated computer as in earlier military radars.

From the front, the radar looks rather like a fly's eye, made up of approximately 2000 facets. On closer examine, each facet is a combined transmitter-receiver element, with approximately 4 watts of output power in the X-Band. They can be activated in arbitrary manner, although a given 15-gram element can either transmit or receive at any given time. The use of solid-state transmitters is a major change from the traveling wave tubes used in earlier military radars. It has been suggested that the individual elements may be made common with those of the F-35 Joint Strike Fighter radar.[2]

Extremely complex, hard-to-intercept beams can be constructed from these individual element transmissions and individually tunable receivers. Multiple beams can be formed for multiple simultaneous functions, such as air-to-air and ground mapping