Inventors:
Moayyed A. Hussain - Menands NY
Kai-Bor Yu - Schenectady NY
Koeunyi Bae - Ithaca NY
Assignee:
Martin Marietta Corp. - Moorestown NJ
International Classification:
H01Q 300
Abstract:
An active array antenna for use, for example, in a radar system, includes elemental antennas, each with a T/R module, distributed over a circular aperture. For lowest cost, the aperture is thinned. The T/R modules are operated at maximum output, to achieve maximum DC-to-RF efficiency, and for simplicity. A phase controller controls the phase shift which is imparted by each module to its signal, to form a main beam and its associated sidelobes. A perturbation phase generator portion of a phase controller adds a perturbation phase shift selected, in conjunction with a particular thinning distribution, to form a relatively wide null in the sidelobe structure, in which signal transduction is reduced. In a radar context, this null may be placed on a source of ground clutter or a jammer.