Patent ID: 7102571
Filing Date: 2006-09-05
Classification: H01Q

Abstract:
1. An antenna having maximum gain at a gain angle with respect to a specified axis of the antenna, the antenna comprising: a substantially planar conductive ground plane element normal to the specified axis; a substantially planar first layer, parallel to and having a first spaced apart relation from the ground plane element, said first layer comprising an array of antenna elements wherein each of at least a plurality of the first layer antenna elements is tuned to a fundamental mode for radiation of a specified frequency, a plurality of the antenna elements being so positioned with respect to one another that isotropic radiation from those elements' positions at the specified frequency would exhibit grating lobes; at least one substantially planar additional layer, each said additional layer parallel to and having a respective maintained spaced apart relation from the first layer, each said additional layer comprising an array of antenna elements wherein each of at least a plurality of the respective additional layer antenna elements is tuned to the fundamental mode, corresponds to a specified first layer antenna element, and is maintained so offset from said specified first layer antenna element in a direction normal to the specified axis as to form therewith a composite antenna element whose antenna pattern exhibits a maximum in a direction offset from normal to the ground plane; and phasing elements for so applying different phases to adjacent elements of the first array that the composite antenna element's antenna pattern exhibits relative attenuation in some said grating lobes' directions.