Patent ID: 7577464
Filing Date: 2009-08-18
Classification: G01S,H01Q

Abstract:
1. An antenna system for use in interference suppression and direction finding, said system comprising: a direction-finding antenna having at least two fundamental modes and including at least one loaded driven element capable of producing angle-of-arrival measurements for received signals and wherein each said loaded driven element includes at least one load port; a plurality of load circuits respectively connected to the load ports and embedded either in the radiation aperture of the antenna or behind a ground plane of said antenna, said load circuits having impedance characteristics that are either (a) predetermined and fixed or (b) variable by changing the values of electrical control signals applied to active components within the load circuits; and a controller configured to select for use a subset of said load circuits to effect operation in at least one of said fundamental modes and which updates control settings of the selected load circuits having variable impedance and belonging to said subset, if any.