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New NG-Built Lightweight Distributed User Coverage Antennas Cut Cost, Save Weight for Milstar Mediu

Northrop Grumman-developed distributed user coverage antennas (DUCAs) for the medium data rate (MDR) communications payload of Milstar satellites produce narrow spot beams. Three DUCAs (each with two reflectors and feeds, as shown) and two accompanying adaptive nulling antennas aboard each MDR payload will enable military users anywhere on Earth to communicate voice, video and data securely at rates as high as 1.544 megabits per second. The DUCAs cost 62 percent less than their counterpart antennas on Milstar's low data rate payload and weigh 72 percent less. Milstar II satellites, beginning with Flight 3, will carry both MDR and LDR payloads. Generally speaking, the DUCAs better match the needs of dispersed global users, such as the U.S. Navy. The nulling antennas, which have the ability to detect and screen out electronic signal-jamming by enemy forces, are better suited to theater-type requirements, where a jammer is likely to be located in the same antenna beam as Milstar users.