Northrop Grumman has started integration of two high-speed downlink phased array antennas in the protected communications payload designed for the US Air Force's (USAF) fourth advanced extremely high frequency (AEHF) satellite.
Called super high frequency array unit (SAU), the antennas were delivered to the AEHF system prime contractor, Lockheed Martin, earlier this month, and are being integrated into the payload, while Lockheed is incorporating the satellite bus unit within the system module, under a hybrid integration plan.
Built by Northrop's Antenna Products Center, the antennas are claimed to be the first to operate at 20GHz in space, and are designed to provide assured point-to-point connectivity using electronically steerable beams that reach military users at fixed-site and mobile terminals.
The high-speed uplink phased array antennas can also operate at 40GHz, providing direct radio frequency beams electronically rather than by moving reflectors mechanically.
The AEHF anti-jam payloads communicate through super high frequency downlinks, transmitting in the 20.2GHz to 21.2GHz frequency band, and EHF uplinks, which also are the first to operate at 40GHz in space.
Northrop Grumman Aerospace Systems Communication Programs vice-president Stuart Linsky said, "This allows one array to do the job of many reflectors, giving the flexibility to point-on-demand in fractions of a second to hundreds of coverage areas, greatly improving access and automatically countering signal jamming by adversaries."
A follow-on to USAF's Milstar system, the AEHF is the next-generation of protected military satellite communications system designed to provide enhanced global, survivable, protected communications for the US troops and its allied militaries, including the UK, Canada and Netherlands.
Equipped with phased array antennas that can block out potential jamming sources, the satellite provides critical survivable, protected and endurable communications links to national leaders, including presidential conferencing during all levels of conflict.
Northrop has also supplied uplink phased array (UPA) high-efficiency converter, commercial application specific integrated circuits,hardware comprising electromechanical switches, passive microwave filters and beam select switch assemblies for the satellites.
Image: An artist impression of USAF's advanced extremely high frequency satellite in orbit. Photo: courtesy of USAF (Los Angeles AFB).