TRW HAS COMPLETED tests on an anti-jam antenna for use on Lockheed Martin Milstar II ultra-secure communications satellites being built for the US Department of Defense.

The space-borne nulling antenna, claimed to be the first system able to detect and defeat enemy jammers in real time, changes its reception pattern in response to incoming signals. It creates nulls to isolate jamming interference from user transmissions.

TRW's Space & Electronics Group is to deliver eight antennas to Hughes Space & Communications, which is building the medium-data-rate payloads for four Milstar II satellites, the first of which is to be launched in late 1998. Each satellite will also have a low-data-rate communications payload produced by TRW.

The testing at TRW's far-field antenna test-range at San Juan Capistrano, California pitted an engineering prototype of the antenna against static and dynamic jamming signals. It was designed to verify a computer model of the antenna's performance, which will be used to predict its on-orbit performance against more exotic jamming. The model also eliminates the need for outdoor-range testing.

Milstar satellites will provide secure, survivable, communications for the US Army, Navy and Air Force.

Source: Flight International