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US 5,872,547 AGranted
Conical omni-directional coverage multibeam antenna with parasitic elements
AssigneeMetawave Communications Corporation
InventorGary Allen Martek
Life of this patent
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AssigneeMetawave Communications Corporation
InventorGary Allen Martek
Estimating the term…
An omni directional coverage multibeam antenna relief on a ground surface having simple conical shapes to provide beam steering. One advantage of such a system is that the projected area is always constant and broadside to the intended direction resulting in limited scan loss effects. In the case of a cylinder as the conical shape, z-axis symmetry provides a constant antenna aperture projection in any azimuthal direction. Using this geometry, high level, side lobes are reduced considerably because of the natural aperture tapering from dispersion effects. These side lobes are further reduced by the presence of parasitic elements which also result in the added benefit of an increased front and back ratio. This front to back ratio may be further increased by the use of inverted cosine energization of selected antenna elements. Coverage area and power can be controlled by changing the ground surface angle and by selectively activating different antenna beam positions around the circumference of the ground surface, and by selectively changing the phase relationship between a given set of antenna beams.
An antenna system comprising:
A selectively directional antenna system comprising:
A method of operating an antenna system having a plurality of radiating structures spaced circumferentially around a center point, each radiating structure spaced equidistant from and parallel to a next adjacent radiating structure, said antenna system also having a plurality of parasitic structures spaced circumferentially around the center point, each parasitic structure spaced equidistant from and parallel to a next adjacent parasitic structure, each parasitic structure also spaced equidistant from and parallel to each radiating structure of a pair of said radiating structures, wherein a ground surface is circumferentially located around the center point and between the center point and each of the radiating structures and the ground surface is also located between the center point and each of the parasitic structures, the method comprising the steps of:
A method of constructing an antenna system comprising the steps of:
A method of energizing an antenna array to result in a far field radiation pattern having acceptably small side lobes in relation to a main lobe, said antenna array having a plurality of radiating structures spaced circumferentially around a center point, said antenna system also having a plurality of parasitic structures spaced circumferentially around the center point, wherein a ground surface is circumferentially located around the center point and between the center point and each of the radiating structures, and wherein the ground surface is also located between the center point and each of the parasitic structures, the method comprising the steps of:
Dependencies are inferred from the claim text.