An Adaptive Nulling Antenna for Military Satellite Communications

• Using adaptive nulling, an antenna system can reconfigure the receive antenna to produce nulls at the locations of any interference sources. Typically, two generic types of adaptive nulling antennas are considered: the thinned phased array and the multiple-beam antenna. The thinned phased array has excellent nulling resolution but is not a good candidate for area coverage. The multiple/beam antenna, on the other hand, can provide good area coverage but has poorer nulling resolution. Lincoln Laboratory has constructed and demonstrated an antenna system that combines the desirable qualities of both types of antennas with the added advantages of multiple simultaneous beam service and extremely light weight. Designed to withstand the rigors of both a launch and a space environment, the antenna produces three simultaneous electronically agile beams, anyone ofwhich can be used for area coverage. The antenna operates in the 43.5-to-45.5-GHz band and is capable of producing broadband nulls at least 30 dB deep with a resolution of about 0.1 0 • Weighing slightly less than 561b, the antenna is a viable candidate for military satellite communications.