Patent ID: 6661378
Filing Date: 2003-12-09
Classification: G01S,H01Q

Abstract:
An active high density multi-element antenna system for radiolocation by identification of the direction of RF radiation from a target source, comprisingantenna elements configured in multiple concentric rings about a central axis to define arcuate sectors about the central axis, each of the multiple concentric rings including a plurality of adjacent discrete antenna elements within each sector, the rings having diameter decreasing radially inwardly toward the central axis, each of the elements in the concentric rings have mutual relation to corresponding elements in at least one other of the concentric rings, such that corresponding elements in the multiple rings define respective antenna units which are radial to the central axis, said antenna units being each defined by respective radially corresponding discrete antenna elements in at least two of the multiple concentric rings, the discrete antenna elements constituting each of the antenna units are formed by upright conductive elements for each of the multiple concentric rings, the upright conductive antenna elements for each of the multiple concentric rings being carried by radially spaced printed circuits having surfaces defining the respective rings, each of the antenna units being selectively operatively enabled or selectively operatively disabled in rotational sequence by rotation about the central axis to provide signal selectivity in a narrow beam width defined by the respective radially corresponding antenna units and whereby the selectivity is rotatable about the central axis, feedpoints for each of the antenna units for receiving received RF signals from the respective antenna units when enabled, array means for controllably enabling and disabling the antenna units to cause RF scanning of the antenna units about the central axis and within a least a selected one of the sectors, the array means being operable for identifying which antenna unit within the selected sector is representative of an azimuth representing the direction to the target source.