Dual polarization flat plate antenna
First Claim
1. A linearly polarized antenna for producing two coincident broadside beams with said beams having their polarizations orthogonal, comprising:
- a top plate;
a bottom plate delimiting with said top plate a cavity in which a first higher order rectangular waveguide mode having a mode number P propagates in a first direction in the cavity, and a second and independent higher order rectangular waveguide mode having a mode number Q propagates in a second direction in the cavity, said first direction being orthogonal to said second direction, said top plate having a first set of radiating slots through it, all slots of said first set being parallel to a Y-axis of a cartesian coordinate system and arranged in P-1 rows of alternatingly staggered parallel radiating slots and Q columns of colinear radiating slots, and a second set of radiating slots, all slots of said second set being parallel to an X-axis of a cartesian coordinate system and arranged in P rows of colinear radiating slots and Q-1 columns of alternately staggered parallel radiating slots, the slots of said first and second sets having respective first and second longitudinal axes, the longitudinal axes of said first and second sets being perpendicular to one another.
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Accused Products
Abstract
A flat plate array is provided which permits generation of two independent beams from a single slotted waveguide antenna. The two beams are coincident in space, but are of two different linear polarizations, those polarizations being orthogonal, i.e., at right angles to each other. In the preferred embodiment, a plurality of slots are provided in a flat top plate of a waveguide cavity. The slots are located in rows and columns with a predetermined spacing between pairs of slots positioned in the respective rows and columns. Each beam is associated with its own input/output port and either the rows or columns of slots of the array. Coupling the two ports with a suitable power splitter and phase shifter permits the antenna to produce a single beam with any elliptical polarization, any linear polarization, right circular polarization, or left circular polarization, plus a second coincident beam with polarization characteristics "orthogonal" to the first, for example, right circular polarization and left circular polarization.
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Citations
17 Claims
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1. A linearly polarized antenna for producing two coincident broadside beams with said beams having their polarizations orthogonal, comprising:
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a top plate; a bottom plate delimiting with said top plate a cavity in which a first higher order rectangular waveguide mode having a mode number P propagates in a first direction in the cavity, and a second and independent higher order rectangular waveguide mode having a mode number Q propagates in a second direction in the cavity, said first direction being orthogonal to said second direction, said top plate having a first set of radiating slots through it, all slots of said first set being parallel to a Y-axis of a cartesian coordinate system and arranged in P-1 rows of alternatingly staggered parallel radiating slots and Q columns of colinear radiating slots, and a second set of radiating slots, all slots of said second set being parallel to an X-axis of a cartesian coordinate system and arranged in P rows of colinear radiating slots and Q-1 columns of alternately staggered parallel radiating slots, the slots of said first and second sets having respective first and second longitudinal axes, the longitudinal axes of said first and second sets being perpendicular to one another. - View Dependent Claims (2, 3, 4)
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5. A dual polarization flat plate array, comprising:
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a top plate; a bottom palte; and at least first and second side walls operatively connected to said top and said bottom plate so as to define a cavity therebetween, said first side wall having a first predetermined number of slots disposed therein to excite an electromagnetic wave mode to propagate perpendicularly with respect to the first side wall across the cavity, said second side wall having a second predetermined number of slots therein to excite an electromagnetic wave mode to propagate perpendicularly with respect to the second side wall across the cavity, the first and second walls being disposed such that their respective electromagnetic wave modes are orthogonal, said top plate having a plurality of slots formed in it, said slots being arranged in a plurality of generally parallel rows and columns, each of said generally parallel rows and columns having respective alignment axes, each of said rows having first and second ones of said slots defining a slot pair, said slot pair having a first spacing between them, a second spacing between succeeding ones of said slot pairs;
first and second ones of said slots of said columns defining a slot pair, said slot pair said columns having a first spacing between them a second spacing between successive ones of said slot pairs in said columns, successive ones of said parallel rows having a staggered relationship with respect to one another, successive ones of said parallel columns having a staggered relationship with respect to one another, the slots of said rows and the slots of said columns being positioned so that the axes of the rows and columns cross one another perpendicularly outside all slots along said first spacing, said rows of slots being disposed so as to couple only with the electromagnetic wave mode associated with the first side wall and the columns of slots being disposed so as to couple only with the electromagnetic wave mode associated with the second side wall. - View Dependent Claims (6, 7, 8, 9, 10)
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11. A flat plate array, comprising:
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a top plate; a bottom plate; and a plurality of side walls including first and second sidewalls operatively connected to said top plate and said bottom plate so as to define a cavity therebetween, said first side wall having a first predetermined number Q of slots disposed therein to excite an electromagnetic wave mode to propagate perpendicularly with respect to the first side wall across the cavity, said second side wall having a second predetermined number of slots P therein to excite an electromagnetic wave mode to propagate perpendicularly with respect to the second side wall across the cavity, the first and second walls being disposed such that their respective electromagnetic wave modes are orthogonal, said top plate having a first set of radiating slots through it, the slots of said first set being parallel to one another and arranged in P-1 rows of alternatingly staggered parallel radiating slots and having Q columns of colinear radiating slots, and a second set of radiating slots, the slots of said second set being arranged in Q-1 columns of alternatingly staggered parallel slots and P rows of colinear radiating slots, said P rows and Q columns having a longitudinal axis perpendicular to one another, the longitudinal axes of said respective slot sets being perpendicular to one another.
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12. An antenna array, comprising:
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a top plate; a bottom plate generally parallel to the top plate; a first set of oppositely opposed side walls formed by waveguide caivites, each of said opposed side walls having a first predetermined number of slots disposed therein to excite an electromagnetic wave mode to propagate between the first set of opposed side walls; a second set of oppositely opposed side walls formed by waveguide cavities, each of the opposed side walls of the second set having a second predetermined number of slots disposed therein to excite an eletromagnetic wave mode to propagate between the second set of opposed side walls, said first and second sets of opposed side walls being operatively connected to said top and bottom plate so as to define a cavity therebetween; said top plate having a plurality of slots formed in it, said slots being arranged in a plurality of generally parallel rows having longitudinal axes in a first direction, and a plurality of columns having longitudinal axes perpendicular to the longitudinal axes of said rows, the slots of said rows defining a plurality of slot pairs having a first distance between them, respective ones of said slot pairs being separated by a second distance;
the slots of said columns defining a plurality of slot pairs having a first distance between them, respective ones of said slot pairs being separated by a second distance; and
means for perturbing the electrical field in said cavity, said rows of slots being disposed so as to couple only with the electromagnetic wave mode associated with the first set of side walls and the columns of slots being disposed as as to couple only with the electromagnetic wave mode associated with the second set of side walls. - View Dependent Claims (13, 14, 15, 16, 17)
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Specification