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The USAF’s new B-21 Raider strategic bomber may use active RF decoys to enhance its protection against radar-guided missiles.

The USAF’s new B-21 bomber may be outfitted with active jamming decoys to enhance self protection.

Sources close to the United States Air Force (USAF) Electronic Warfare (EW) community have told Armada that Northrop Grumman may be developing an active Radio Frequency (RF) countermeasure. The decoy could be launched from standard combat aircraft countermeasure dispensers. It would protect against radar-guided Surface-to-Air and Air-to-Air Missiles (SAMs/AAMs). Such a decoy may emit jamming signals on frequencies of 8.5 gigahertz/GHz and above. This would be sufficient to attack active and semi-active radar homing seekers routinely used by SAMs and AAMs. These weapons use X-band (8.5GHz to 10.68GHz), Ku-band (13.4GHz to 14GHz/15.7GHz to 17.7GHz), K-band (24.05GHz to 24.25GHz) and Ka-band (33.4GHz to 36GHz) radar seekers. The relatively short wavelengths of these frequencies, 35mm to 8.3mm, gives a sharp image of the missile’s target enhance precision.

The decoy maybe capable of transmitting standard spot and barrage jamming waveforms. The addition of a digital RF memory would allow transmission of complex, discreet jamming techniques. These could help overcome missile electronic counter-counter measures. The decoy would provide last ditch protection against incoming SAMs and AAMs during the missile’s endgame.

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Interest in active RF decoys is gaining momentum. The Royal Air Force performed trials with Leonardo’s BriteCloud family of countermeasures onboard its Eurofighter Typhoon F/GR4 combat aircraft in 2019. That same year, it was revealed that the US Air National Guard would evaluate the BriteCloud decoy.

Further information on Northrop Grumman’s active RF decoy is scant. Speculation is focusing on the decoy as an enhancement to the self-defence systems onboard the USAF’s forthcoming B-21 Raider strategic bomber. The company is the prime contractor for this aircraft expected to include other avantgarde self-protection kit like a kinetic anti-missile system.

Armada asked Northrop Grumman for more information on the active RF decoy. The company told us via a written statement that it was “advancing the state-of-the-art in low-size, weight and power technologies for active radio frequency countermeasures and decoys that can protect a wide range of platforms, including aircraft and surface vessels.” This seems to be an implicit admission that the technology is under development, although the firm declined to provide more details.

Extensive investments in ground-based air defence technology by the People’s Republic of China and Russia means that the B-21 will be arguably the best protected aircraft of its kind when it enters service in circa 2025. Equipping the jet to launch active RF decoys will be an important part of this effort.

by Dr. Thomas Withington