Low cost antenna array and methods of manufacture
In some embodiments, an apparatus may include a conductive planar structure having a plurality of antenna elements and a plurality of cutout portions. The plurality of cutout portions may define a combiner circuit including an output interface and including a combiner circuit coupled between each of the plurality of antenna elements and the output interface.
1. An apparatus comprising:
a conductive planar structure including:
a plurality of antenna elements;
a plurality of cutout portions defining a circuit including an output interface and including a combiner circuit coupled between each of the plurality of antenna elements and the output interface; and
at least one spacer configured to couple to the conductive planar structure to form an antenna column, the at least one spacer configured to provide a ground plane and including a plurality of etched portions corresponding to the cutout portions of the conductive planar structure.
2. The apparatus of claim 1 , wherein the plurality of antenna elements are arranged in a common plane.
3. The apparatus of claim 1 , wherein the antenna column may be coupled to one or more other antenna columns to form an antenna array.
4. The apparatus of claim 3 , wherein:
the antenna column may include the plurality of antenna elements extending in a first plane; and
at least one of the one or more other antenna columns may include a plurality of antenna elements extending in a second plane.
5. The apparatus of claim 4 , wherein the first plane is orthogonal to the second plane.
6. The apparatus of claim 1 , wherein the conductive planar structure and the at least one spacer may be adjusted geometrically to receive radio frequency signals at selected frequencies.
7. The apparatus of claim 1 , wherein the plurality of cutout portions forms a symmetric configuration of circuit elements.
8. The apparatus of claim 1 , wherein the combiner circuit includes one or more stub shorts configured to provide impedance mismatch cancellation.
9. The apparatus of claim 1 , wherein the at least one spacer is formed from a unitary piece of material.
10. A method comprising:
providing a conductive antenna structure having multiple antenna elements, an output interface, and an integrated combiner circuit coupling the multiple antenna elements to the output interface, the multiple antenna elements, the output interface and the integrated combiner circuit formed from a sheet of electrically conductive material; and
coupling a spacer to the conductive antenna structure to form an antenna column, the spacer formed from a conductive material and configured to provide a ground plane, the spacer including recesses configured to provide an air gap between the spacer and the integrated combiner circuit.
11. The method of claim 10 , further comprising:
providing a second conductive antenna structure having multiple antenna elements, an output interface, and a second integrated combiner circuit coupling the multiple antenna elements to the output interface, the multiple antenna elements, the output interface, and the second integrated combiner circuit of the second conductive antenna formed from a second sheet of electrically conductive material;
coupling a second spacer to the conductive antenna structure to form an second antenna column; and
coupling the antenna column to the second antenna column to form an antenna array.
12. The method of claim 11 , further comprising:
combining signals from each of the multiple antenna elements of the monolithic, conductive antenna structure using the integrated combiner circuit;
combining signals from each of the multiple antenna elements of the second monolithic, conductive antenna structure using the second integrated combiner circuit; and
combining output signals from the integrated combiner circuit and the second integrated combiner circuit using a third combiner circuit.
13. The method of claim 10 , wherein before coupling the spacer, the method further comprising removing portions of the spacer to provide an air dielectric around the conductors of the monolithic, conductive antenna structure.
14. The method of claim 10 , wherein providing the monolithic, conductive antenna structure comprises:
forming the multiple antenna elements, an output interface, and an integrated combiner circuit from a sheet of conductive material, the integrated combiner circuit formed from a plurality of cutout portions defining strip-line conductors coupling the multiple antenna elements to the output interface.
15. The method of claim 10 , wherein the spacer is formed from a unitary piece of material.
16. An apparatus comprising:
an antenna structure formed from sheet of conductive material in a plane, the antenna structure including:
an output interface;
a plurality of antenna elements;
a combiner circuit formed from a plurality of cutout portions defining strip-line conductors extending between the plurality of antenna elements and the output interface; and
at least one spacer configured to couple to the conductive planar structure to form an antenna column, the at least one spacer including a plurality of indentations corresponding to the strip-line conductors of the combiner circuit to provide an air gap between the strip-line conductors and the at least one spacer.
17. The apparatus of claim 16 , wherein the at least one spacer is formed of a conductive material and is configured to form a ground plane.
18. The apparatus of claim 16 , wherein the combiner circuit includes at least one impedance mismatch cancellation stub coupled between one of the strip-line conductors and the at least one spacer.
19. The apparatus of claim 16 , wherein the spacer comprises:
a molded plastic substrate; and
a conductive coating on surfaces of the molded plastic substrate.