AN/APG-77 AESA Radar

AN/APG-77 AESA Radar

Northrop Grumman's AN/APG-77 radar employs a different type of electronically scanned phased array. In what is likely to be the most advanced airborne radar in the world, individual transmit and receive modules will be located behind each element of the radar array. The transmit function of the solid-state microwave modules will supplant the travelling wave tubes used in prior radars like the APQ-164.

The AESA configuration will have a wider transmit bandwidth while requiring significantly less volume and prime power. The system represents about half the weight of an equivalent passive ESA design. Each of the hundreds of individual solid-state devices generates only small amounts of power, but the aggregate for the entire array will be substantial.

Reliability and life-cycle costs

The APG-77's active aperture antenna offers attractive benefits. The system exhibits a very low radar cross section, supporting the F-22's stealthy design. Reliability of the all-solid-state system is expected to be substantially better than the already highly reliable F-16 radar, with MTBF predicted at more than 450 hours. AESA life-cycle costs are expected to be significantly lower than those of MSAs. The active arrays on the F-22 should have almost twice the expected life of the airframe.

Synthetic Aperture Radar (SAR) capability

Northrop Grumman has successfully demonstrated the capability to generate high-resolution, in-flight synthetic aperture radar (SAR) maps. Flight tests, on board a company BAC 1-11 test bed aircraft, have proved that the F-22 fighter's mission capabilities have expanded to include directly identifying and targeting enemy ground defenses and mobile forces.

Technical experience and features

  • All performance specifications have been met or exceeded.
  • Weapons System Integration - Integrated an LPI, AESA radar into a tactical avionics and weapons suite.
  • Supportability - designed for two-level maintenance and high reliability (MTBF over 450 hours).

Northrop Grumman ES is responsible for the overall design of the AN/APG-77 radar system, including the control and signal processing software. Northrop Grumman also has responsibility for radar systems integration and test activities. The main component of the radar sensor is a highly reliable Active Electronically Scanned Array (AESA), which provides the rapid beam agility, low radar cross section and target detection capability that enables the air dominance fighter to achieve "first look, first kill" capability. The system exhibits a very low radar cross section, supporting the F-22's stealthy design.